diff --git a/.github/hooks/pre-commit.sh b/.github/hooks/pre-commit.sh
index cc318d7..d5a1ce5 100755
--- a/.github/hooks/pre-commit.sh
+++ b/.github/hooks/pre-commit.sh
@@ -10,3 +10,4 @@
 exec 1>&2
 
 .github/lint-disallowed-functions-in-library.sh
+.github/lint-no-trailing-newline-in-log-messages.sh
diff --git a/.github/lint-no-trailing-newline-in-log-messages.sh b/.github/lint-no-trailing-newline-in-log-messages.sh
new file mode 100755
index 0000000..29cd4a2
--- /dev/null
+++ b/.github/lint-no-trailing-newline-in-log-messages.sh
@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+
+#
+# DO NOT EDIT THIS FILE
+#
+# It is automatically copied from https://github.com/pion/.goassets repository.
+#
+# If you want to update the shared CI config, send a PR to
+# https://github.com/pion/.goassets instead of this repository.
+#
+
+set -e
+
+# Disallow usages of functions that cause the program to exit in the library code
+SCRIPT_PATH=$( cd "$(dirname "${BASH_SOURCE[0]}")" ; pwd -P )
+if [ -f ${SCRIPT_PATH}/.ci.conf ]
+then
+  . ${SCRIPT_PATH}/.ci.conf
+fi
+
+files=$(
+  find "$SCRIPT_PATH/.." -name "*.go" \
+    | while read file
+    do
+      excluded=false
+      for ex in $EXCLUDE_DIRECTORIES
+      do
+        if [[ $file == */$ex/* ]]
+        then
+          excluded=true
+          break
+        fi
+      done
+      $excluded || echo "$file"
+    done
+)
+
+if grep -E '\.(Trace|Debug|Info|Warn|Error)f?\("[^"]*\\n"\)?' $files | grep -v -e 'nolint'; then
+	echo "Log format strings should have trailing new-line"
+	exit 1
+fi
\ No newline at end of file
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
new file mode 100644
index 0000000..cec0d7c
--- /dev/null
+++ b/.github/workflows/codeql-analysis.yml
@@ -0,0 +1,40 @@
+name: "CodeQL"
+
+on:
+  workflow_dispatch:
+  schedule:
+    - cron: '23 5 * * 0'
+  pull_request:
+    branches:
+      - master
+    paths:
+      - '**.go'
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    permissions:
+      actions: read
+      contents: read
+      security-events: write
+
+    steps:
+    - name: Checkout repo
+      uses: actions/checkout@v3
+
+    # The code in examples/ might intentionally do things like log credentials
+    # in order to show how the library is used, aid in debugging etc. We
+    # should ignore those for CodeQL scanning, and only focus on the package
+    # itself.
+    - name: Remove example code
+      run: |
+        rm -rf examples/
+
+    - name: Initialize CodeQL
+      uses: github/codeql-action/init@v2
+      with:
+        languages: 'go'
+
+    - name: CodeQL Analysis
+      uses: github/codeql-action/analyze@v2
diff --git a/.github/workflows/generate-authors.yml b/.github/workflows/generate-authors.yml
index 9a80a48..c7a8404 100644
--- a/.github/workflows/generate-authors.yml
+++ b/.github/workflows/generate-authors.yml
@@ -16,6 +16,8 @@ on:
 
 jobs:
   checksecret:
+    permissions:
+      contents: none
     runs-on: ubuntu-latest
     outputs:
       is_PIONBOT_PRIVATE_KEY_set: ${{ steps.checksecret_job.outputs.is_PIONBOT_PRIVATE_KEY_set }}
@@ -28,6 +30,8 @@ jobs:
           echo "::set-output name=is_PIONBOT_PRIVATE_KEY_set::${{ env.PIONBOT_PRIVATE_KEY != '' }}"
 
   generate-authors:
+    permissions:
+      contents: write
     needs: [checksecret]
     if: needs.checksecret.outputs.is_PIONBOT_PRIVATE_KEY_set == 'true'
     runs-on: ubuntu-latest
diff --git a/.github/workflows/lint.yaml b/.github/workflows/lint.yaml
index 438443f..11b6336 100644
--- a/.github/workflows/lint.yaml
+++ b/.github/workflows/lint.yaml
@@ -16,6 +16,10 @@ on:
       - opened
       - edited
       - synchronize
+
+permissions:
+  contents: read
+
 jobs:
   lint-commit-message:
     name: Metadata
@@ -36,8 +40,14 @@ jobs:
         - name: Functions
           run: .github/lint-disallowed-functions-in-library.sh
 
+        - name: Logging messages should not have trailing newlines
+          run: .github/lint-no-trailing-newline-in-log-messages.sh
+
   lint-go:
     name: Go
+    permissions:
+      contents: read
+      pull-requests: read
     runs-on: ubuntu-latest
     strategy:
       fail-fast: false
@@ -47,5 +57,5 @@ jobs:
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v3
         with:
-          version: v1.31
+          version: v1.45.2
           args: $GOLANGCI_LINT_EXRA_ARGS
diff --git a/.github/workflows/renovate-go-mod-fix.yaml b/.github/workflows/renovate-go-mod-fix.yaml
index 5991822..0804642 100644
--- a/.github/workflows/renovate-go-mod-fix.yaml
+++ b/.github/workflows/renovate-go-mod-fix.yaml
@@ -15,6 +15,9 @@ on:
     branches:
       - renovate/*
 
+permissions:
+  contents: write
+
 jobs:
   go-mod-fix:
     runs-on: ubuntu-latest
diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index cd788c9..300fac6 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -17,18 +17,22 @@ on:
   pull_request:
     branches:
     - master
+
+permissions:
+  contents: read
+
 jobs:
   test:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: ["1.16", "1.17"]
+        go: ["1.17", "1.18"]
       fail-fast: false
     name: Go ${{ matrix.go }}
     steps:
       - uses: actions/checkout@v3
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v3
         with:
           path: |
             ~/go/pkg/mod
@@ -44,18 +48,31 @@ jobs:
           go-version: ${{ matrix.go }}
 
       - name: Setup go-acc
-        run: |
-          go get github.com/ory/go-acc
-          git checkout go.mod go.sum
+        run: go install github.com/ory/go-acc@latest
+
+      - name: Set up gotestfmt
+        uses: haveyoudebuggedit/gotestfmt-action@v2
+        with:
+          token: ${{ secrets.GITHUB_TOKEN }} # Avoid getting rate limited
 
       - name: Run test
         run: |
           TEST_BENCH_OPTION="-bench=."
           if [ -f .github/.ci.conf ]; then . .github/.ci.conf; fi
 
+          set -euo pipefail
           go-acc -o cover.out ./... -- \
             ${TEST_BENCH_OPTION} \
-            -v -race
+            -json \
+            -v -race 2>&1 | grep -v '^go: downloading' | tee /tmp/gotest.log | gotestfmt
+
+      - name: Upload test log
+        uses: actions/upload-artifact@v2
+        if: always()
+        with:
+          name: test-log-${{ matrix.go }}
+          path: /tmp/gotest.log
+          if-no-files-found: error
 
       - name: Run TEST_HOOK
         run: |
@@ -64,7 +81,6 @@ jobs:
 
       - uses: codecov/codecov-action@v2
         with:
-          file: ./cover.out
           name: codecov-umbrella
           fail_ci_if_error: true
           flags: go
@@ -73,13 +89,13 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: ["1.16", "1.17"]
+        go: ["1.17", "1.18"]
       fail-fast: false
     name: Go i386 ${{ matrix.go }}
     steps:
       - uses: actions/checkout@v3
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v3
         with:
           path: |
             ~/go/pkg/mod
@@ -117,7 +133,7 @@ jobs:
         with:
           node-version: '16.x'
 
-      - uses: actions/cache@v2
+      - uses: actions/cache@v3
         with:
           path: |
             ~/go/pkg/mod
@@ -153,7 +169,6 @@ jobs:
 
       - uses: codecov/codecov-action@v2
         with:
-          file: ./cover.out
           name: codecov-umbrella
           fail_ci_if_error: true
           flags: wasm
diff --git a/.github/workflows/tidy-check.yaml b/.github/workflows/tidy-check.yaml
index 3ab2c35..fa52ce9 100644
--- a/.github/workflows/tidy-check.yaml
+++ b/.github/workflows/tidy-check.yaml
@@ -18,6 +18,9 @@ on:
     branches:
       - master
 
+permissions:
+  contents: read
+
 jobs:
   Check:
     runs-on: ubuntu-latest
diff --git a/.golangci.yml b/.golangci.yml
index d6162c9..d7a88ec 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -15,14 +15,22 @@ linters-settings:
 linters:
   enable:
     - asciicheck       # Simple linter to check that your code does not contain non-ASCII identifiers
+    - bidichk          # Checks for dangerous unicode character sequences
     - bodyclose        # checks whether HTTP response body is closed successfully
+    - contextcheck     # check the function whether use a non-inherited context
     - deadcode         # Finds unused code
+    - decorder         # check declaration order and count of types, constants, variables and functions
     - depguard         # Go linter that checks if package imports are in a list of acceptable packages
     - dogsled          # Checks assignments with too many blank identifiers (e.g. x, _, _, _, := f())
     - dupl             # Tool for code clone detection
+    - durationcheck    # check for two durations multiplied together
     - errcheck         # Errcheck is a program for checking for unchecked errors in go programs. These unchecked errors can be critical bugs in some cases
+    - errchkjson       # Checks types passed to the json encoding functions. Reports unsupported types and optionally reports occations, where the check for the returned error can be omitted.
+    - errname          # Checks that sentinel errors are prefixed with the `Err` and error types are suffixed with the `Error`.
+    - errorlint        # errorlint is a linter for that can be used to find code that will cause problems with the error wrapping scheme introduced in Go 1.13.
     - exhaustive       # check exhaustiveness of enum switch statements
     - exportloopref    # checks for pointers to enclosing loop variables
+    - forcetypeassert  # finds forced type assertions
     - gci              # Gci control golang package import order and make it always deterministic.
     - gochecknoglobals # Checks that no globals are present in Go code
     - gochecknoinits   # Checks that no init functions are present in Go code
@@ -35,40 +43,62 @@ linters:
     - gofumpt          # Gofumpt checks whether code was gofumpt-ed.
     - goheader         # Checks is file header matches to pattern
     - goimports        # Goimports does everything that gofmt does. Additionally it checks unused imports
-    - golint           # Golint differs from gofmt. Gofmt reformats Go source code, whereas golint prints out style mistakes
+    - gomoddirectives  # Manage the use of 'replace', 'retract', and 'excludes' directives in go.mod.
     - gomodguard       # Allow and block list linter for direct Go module dependencies. This is different from depguard where there are different block types for example version constraints and module recommendations.
     - goprintffuncname # Checks that printf-like functions are named with `f` at the end
     - gosec            # Inspects source code for security problems
     - gosimple         # Linter for Go source code that specializes in simplifying a code
     - govet            # Vet examines Go source code and reports suspicious constructs, such as Printf calls whose arguments do not align with the format string
+    - grouper          # An analyzer to analyze expression groups.
+    - importas         # Enforces consistent import aliases
     - ineffassign      # Detects when assignments to existing variables are not used
     - misspell         # Finds commonly misspelled English words in comments
     - nakedret         # Finds naked returns in functions greater than a specified function length
+    - nilerr           # Finds the code that returns nil even if it checks that the error is not nil.
+    - nilnil           # Checks that there is no simultaneous return of `nil` error and an invalid value.
     - noctx            # noctx finds sending http request without context.Context
-    - scopelint        # Scopelint checks for unpinned variables in go programs
+    - predeclared      # find code that shadows one of Go's predeclared identifiers
+    - revive           # golint replacement, finds style mistakes
     - staticcheck      # Staticcheck is a go vet on steroids, applying a ton of static analysis checks
     - structcheck      # Finds unused struct fields
     - stylecheck       # Stylecheck is a replacement for golint
+    - tagliatelle      # Checks the struct tags.
+    - tenv             # tenv is analyzer that detects using os.Setenv instead of t.Setenv since Go1.17
+    - tparallel        # tparallel detects inappropriate usage of t.Parallel() method in your Go test codes
     - typecheck        # Like the front-end of a Go compiler, parses and type-checks Go code
     - unconvert        # Remove unnecessary type conversions
     - unparam          # Reports unused function parameters
     - unused           # Checks Go code for unused constants, variables, functions and types
     - varcheck         # Finds unused global variables and constants
+    - wastedassign     # wastedassign finds wasted assignment statements
     - whitespace       # Tool for detection of leading and trailing whitespace
   disable:
+    - containedctx     # containedctx is a linter that detects struct contained context.Context field
+    - cyclop           # checks function and package cyclomatic complexity
+    - exhaustivestruct # Checks if all struct's fields are initialized
+    - forbidigo        # Forbids identifiers
     - funlen           # Tool for detection of long functions
     - gocyclo          # Computes and checks the cyclomatic complexity of functions
     - godot            # Check if comments end in a period
     - gomnd            # An analyzer to detect magic numbers.
+    - ifshort          # Checks that your code uses short syntax for if-statements whenever possible
+    - ireturn          # Accept Interfaces, Return Concrete Types
     - lll              # Reports long lines
+    - maintidx         # maintidx measures the maintainability index of each function.
+    - makezero         # Finds slice declarations with non-zero initial length
     - maligned         # Tool to detect Go structs that would take less memory if their fields were sorted
     - nestif           # Reports deeply nested if statements
     - nlreturn         # nlreturn checks for a new line before return and branch statements to increase code clarity
     - nolintlint       # Reports ill-formed or insufficient nolint directives
+    - paralleltest     # paralleltest detects missing usage of t.Parallel() method in your Go test
     - prealloc         # Finds slice declarations that could potentially be preallocated
+    - promlinter       # Check Prometheus metrics naming via promlint
     - rowserrcheck     # checks whether Err of rows is checked successfully
     - sqlclosecheck    # Checks that sql.Rows and sql.Stmt are closed.
     - testpackage      # linter that makes you use a separate _test package
+    - thelper          # thelper detects golang test helpers without t.Helper() call and checks the consistency of test helpers
+    - varnamelen       # checks that the length of a variable's name matches its scope
+    - wrapcheck        # Checks that errors returned from external packages are wrapped
     - wsl              # Whitespace Linter - Forces you to use empty lines!
 
 issues:
diff --git a/AUTHORS.txt b/AUTHORS.txt
index 3606ac9..2b8d45c 100644
--- a/AUTHORS.txt
+++ b/AUTHORS.txt
@@ -4,8 +4,10 @@
 # This file is auto generated, using git to list all individuals contributors.
 # see `.github/generate-authors.sh` for the scripting
 adamroach <adam@nostrum.com>
+Adrian Cable <adrian.cable@gmail.com>
 Agniva De Sarker <agnivade@yahoo.co.in>
 Antoine Baché <antoine@tenten.app>
+Antoine Baché <Antonito@users.noreply.github.com>
 Atsushi Watanabe <atsushi.w@ieee.org>
 backkem <mail@backkem.me>
 chenkaiC4 <chenkaic4@gmail.com>
diff --git a/context.go b/context.go
index e0ad48c..bf871b2 100644
--- a/context.go
+++ b/context.go
@@ -86,9 +86,9 @@ func CreateContext(masterKey, masterSalt []byte, profile ProtectionProfile, opts
 
 	switch profile {
 	case ProtectionProfileAeadAes128Gcm:
-		c.cipher, err = newSrtpCipherAeadAesGcm(masterKey, masterSalt)
-	case ProtectionProfileAes128CmHmacSha1_80:
-		c.cipher, err = newSrtpCipherAesCmHmacSha1(masterKey, masterSalt)
+		c.cipher, err = newSrtpCipherAeadAesGcm(profile, masterKey, masterSalt)
+	case ProtectionProfileAes128CmHmacSha1_32, ProtectionProfileAes128CmHmacSha1_80:
+		c.cipher, err = newSrtpCipherAesCmHmacSha1(profile, masterKey, masterSalt)
 	default:
 		return nil, fmt.Errorf("%w: %#v", errNoSuchSRTPProfile, profile)
 	}
@@ -112,13 +112,13 @@ func CreateContext(masterKey, masterSalt []byte, profile ProtectionProfile, opts
 }
 
 // https://tools.ietf.org/html/rfc3550#appendix-A.1
-func (s *srtpSSRCState) nextRolloverCount(sequenceNumber uint16) (uint32, func()) {
+func (s *srtpSSRCState) nextRolloverCount(sequenceNumber uint16) (uint32, int32) {
 	seq := int32(sequenceNumber)
 	localRoc := uint32(s.index >> 16)
 	localSeq := int32(s.index & (seqNumMax - 1))
 
 	guessRoc := localRoc
-	var difference int32 = 0
+	var difference int32
 
 	if s.rolloverHasProcessed {
 		// When localROC is equal to 0, and entering seq-localSeq > seqNumMedian
@@ -147,15 +147,17 @@ func (s *srtpSSRCState) nextRolloverCount(sequenceNumber uint16) (uint32, func()
 		}
 	}
 
-	return guessRoc, func() {
-		if !s.rolloverHasProcessed {
-			s.index |= uint64(sequenceNumber)
-			s.rolloverHasProcessed = true
-			return
-		}
-		if difference > 0 {
-			s.index += uint64(difference)
-		}
+	return guessRoc, difference
+}
+
+func (s *srtpSSRCState) updateRolloverCount(sequenceNumber uint16, difference int32) {
+	if !s.rolloverHasProcessed {
+		s.index |= uint64(sequenceNumber)
+		s.rolloverHasProcessed = true
+		return
+	}
+	if difference > 0 {
+		s.index += uint64(difference)
 	}
 }
 
diff --git a/context_test.go b/context_test.go
index e5b95f4..b3fecea 100644
--- a/context_test.go
+++ b/context_test.go
@@ -5,7 +5,7 @@ import (
 )
 
 func TestContextROC(t *testing.T) {
-	c, err := CreateContext(make([]byte, 16), make([]byte, 14), cipherContextAlgo)
+	c, err := CreateContext(make([]byte, 16), make([]byte, 14), profileCTR)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -24,7 +24,7 @@ func TestContextROC(t *testing.T) {
 }
 
 func TestContextIndex(t *testing.T) {
-	c, err := CreateContext(make([]byte, 16), make([]byte, 14), cipherContextAlgo)
+	c, err := CreateContext(make([]byte, 16), make([]byte, 14), profileCTR)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/crypto.go b/crypto.go
new file mode 100644
index 0000000..e2eb9b2
--- /dev/null
+++ b/crypto.go
@@ -0,0 +1,58 @@
+package srtp
+
+import (
+	"crypto/cipher"
+)
+
+// xorBytes computes the exclusive-or of src1 and src2 and stores it in dst.
+// It returns the number of bytes written.
+func xorBytes(dst, src1, src2 []byte) int {
+	n := len(src1)
+	if len(src2) < n {
+		n = len(src2)
+	}
+	if len(dst) < n {
+		n = len(dst)
+	}
+
+	for i := 0; i < n; i++ {
+		dst[i] = src1[i] ^ src2[i]
+	}
+
+	return n
+}
+
+// incrementCTR increments a big-endian integer of arbitrary size.
+func incrementCTR(ctr []byte) {
+	for i := len(ctr) - 1; i >= 0; i-- {
+		ctr[i]++
+		if ctr[i] != 0 {
+			break
+		}
+	}
+}
+
+// xorBytesCTR performs CTR encryption and decryption.
+// It is equivalent to cipher.NewCTR followed by XORKeyStream.
+func xorBytesCTR(block cipher.Block, iv []byte, dst, src []byte) error {
+	if len(iv) != block.BlockSize() {
+		return errBadIVLength
+	}
+
+	ctr := make([]byte, len(iv))
+	copy(ctr, iv)
+	bs := block.BlockSize()
+	stream := make([]byte, bs)
+
+	i := 0
+	for i < len(src) {
+		block.Encrypt(stream, ctr)
+		incrementCTR(ctr)
+		n := xorBytes(dst[i:], src[i:], stream)
+		if n == 0 {
+			break
+		}
+		i += n
+	}
+	return nil
+}
diff --git a/crypto_test.go b/crypto_test.go
new file mode 100644
index 0000000..4a5bf8f
--- /dev/null
+++ b/crypto_test.go
@@ -0,0 +1,83 @@
+package srtp
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"math/rand"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func xorBytesCTRReference(block cipher.Block, iv []byte, dst, src []byte) {
+	stream := cipher.NewCTR(block, iv)
+	stream.XORKeyStream(dst, src)
+}
+
+func TestXorBytesCTR(t *testing.T) {
+	for keysize := 16; keysize < 64; keysize *= 2 {
+		key := make([]byte, keysize)
+		_, err := rand.Read(key) //nolint: gosec
+		require.NoError(t, err)
+
+		block, err := aes.NewCipher(key)
+		require.NoError(t, err)
+
+		iv := make([]byte, block.BlockSize())
+		for i := 0; i < 1500; i++ {
+			src := make([]byte, i)
+			dst := make([]byte, i)
+			reference := make([]byte, i)
+			_, err = rand.Read(iv) //nolint: gosec
+			require.NoError(t, err)
+
+			_, err = rand.Read(src) //nolint: gosec
+			require.NoError(t, err)
+
+			assert.NoError(t, xorBytesCTR(block, iv, dst, src))
+			xorBytesCTRReference(block, iv, reference, src)
+			require.Equal(t, dst, reference)
+
+			// test overlap
+			assert.NoError(t, xorBytesCTR(block, iv, dst, dst))
+			xorBytesCTRReference(block, iv, reference, reference)
+			require.Equal(t, dst, reference)
+		}
+	}
+}
+
+func TestXorBytesCTRInvalidIvLength(t *testing.T) {
+	key := make([]byte, 16)
+	block, err := aes.NewCipher(key)
+	require.NoError(t, err)
+
+	src := make([]byte, 1024)
+	dst := make([]byte, 1024)
+
+	test := func(iv []byte) {
+		assert.Error(t, errBadIVLength, xorBytesCTR(block, iv, dst, src))
+	}
+
+	test(make([]byte, block.BlockSize()-1))
+	test(make([]byte, block.BlockSize()+1))
+}
+
+func TestXorBytesBufferSize(t *testing.T) {
+	a := []byte{3}
+	b := []byte{5, 6}
+	dst := make([]byte, 3)
+
+	xorBytes(dst, a, b)
+	require.Equal(t, dst, []byte{6, 0, 0})
+
+	xorBytes(dst, b, a)
+	require.Equal(t, dst, []byte{6, 0, 0})
+
+	a = []byte{1, 1, 1, 1}
+	b = []byte{2, 2, 2, 2}
+	dst = make([]byte, 3)
+
+	xorBytes(dst, a, b)
+	require.Equal(t, dst, []byte{3, 3, 3})
+}
diff --git a/errors.go b/errors.go
index a702621..55a67bc 100644
--- a/errors.go
+++ b/errors.go
@@ -18,6 +18,7 @@ var (
 	errTooShortRTCP                  = errors.New("packet is too short to be rtcp packet")
 	errPayloadDiffers                = errors.New("payload differs")
 	errStartedChannelUsedIncorrectly = errors.New("started channel used incorrectly, should only be closed")
+	errBadIVLength                   = errors.New("bad iv length in xorBytesCTR")
 
 	errStreamNotInited     = errors.New("stream has not been inited, unable to close")
 	errStreamAlreadyClosed = errors.New("stream is already closed")
@@ -25,16 +26,16 @@ var (
 	errFailedTypeAssertion = errors.New("failed to cast child")
 )
 
-type errorDuplicated struct {
+type duplicatedError struct {
 	Proto string // srtp or srtcp
 	SSRC  uint32
 	Index uint32 // sequence number or index
 }
 
-func (e *errorDuplicated) Error() string {
+func (e *duplicatedError) Error() string {
 	return fmt.Sprintf("%s ssrc=%d index=%d: %v", e.Proto, e.SSRC, e.Index, errDuplicated)
 }
 
-func (e *errorDuplicated) Unwrap() error {
+func (e *duplicatedError) Unwrap() error {
 	return errDuplicated
 }
diff --git a/go.mod b/go.mod
index 6af247e..9f0e9a6 100644
--- a/go.mod
+++ b/go.mod
@@ -5,7 +5,7 @@ go 1.14
 require (
 	github.com/pion/logging v0.2.2
 	github.com/pion/rtcp v1.2.9
-	github.com/pion/rtp v1.7.4
+	github.com/pion/rtp v1.7.13
 	github.com/pion/transport v0.13.0
-	github.com/stretchr/testify v1.7.0
+	github.com/stretchr/testify v1.7.1
 )
diff --git a/go.sum b/go.sum
index 836d704..4b2d50e 100644
--- a/go.sum
+++ b/go.sum
@@ -6,15 +6,16 @@ github.com/pion/randutil v0.1.0 h1:CFG1UdESneORglEsnimhUjf33Rwjubwj6xfiOXBa3mA=
 github.com/pion/randutil v0.1.0/go.mod h1:XcJrSMMbbMRhASFVOlj/5hQial/Y8oH/HVo7TBZq+j8=
 github.com/pion/rtcp v1.2.9 h1:1ujStwg++IOLIEoOiIQ2s+qBuJ1VN81KW+9pMPsif+U=
 github.com/pion/rtcp v1.2.9/go.mod h1:qVPhiCzAm4D/rxb6XzKeyZiQK69yJpbUDJSF7TgrqNo=
-github.com/pion/rtp v1.7.4 h1:4dMbjb1SuynU5OpA3kz1zHK+u+eOCQjW3MAeVHf1ODA=
-github.com/pion/rtp v1.7.4/go.mod h1:bDb5n+BFZxXx0Ea7E5qe+klMuqiBrP+w8XSjiWtCUko=
+github.com/pion/rtp v1.7.13 h1:qcHwlmtiI50t1XivvoawdCGTP4Uiypzfrsap+bijcoA=
+github.com/pion/rtp v1.7.13/go.mod h1:bDb5n+BFZxXx0Ea7E5qe+klMuqiBrP+w8XSjiWtCUko=
 github.com/pion/transport v0.13.0 h1:KWTA5ZrQogizzYwPEciGtHPLwpAjE91FgXnyu+Hv2uY=
 github.com/pion/transport v0.13.0/go.mod h1:yxm9uXpK9bpBBWkITk13cLo1y5/ur5VQpG22ny6EP7g=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 golang.org/x/net v0.0.0-20211201190559-0a0e4e1bb54c h1:WtYZ93XtWSO5KlOMgPZu7hXY9WhMZpprvlm5VwvAl8c=
 golang.org/x/net v0.0.0-20211201190559-0a0e4e1bb54c/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
diff --git a/key_derivation.go b/key_derivation.go
index 26386d4..09bc58b 100644
--- a/key_derivation.go
+++ b/key_derivation.go
@@ -48,16 +48,19 @@ func aesCmKeyDerivation(label byte, masterKey, masterSalt []byte, indexOverKdr i
 // -       passing through 65,535
 // i = 2^16 * ROC + SEQ
 // IV = (salt*2 ^ 16) | (ssrc*2 ^ 64) | (i*2 ^ 16)
-func generateCounter(sequenceNumber uint16, rolloverCounter uint32, ssrc uint32, sessionSalt []byte) [16]byte {
-	var counter [16]byte
+func generateCounter(sequenceNumber uint16, rolloverCounter uint32, ssrc uint32, sessionSalt []byte) (counter [16]byte) {
+	copy(counter[:], sessionSalt)
 
-	binary.BigEndian.PutUint32(counter[4:], ssrc)
-	binary.BigEndian.PutUint32(counter[8:], rolloverCounter)
-	binary.BigEndian.PutUint32(counter[12:], uint32(sequenceNumber)<<16)
-
-	for i := range sessionSalt {
-		counter[i] ^= sessionSalt[i]
-	}
+	counter[4] ^= byte(ssrc >> 24)
+	counter[5] ^= byte(ssrc >> 16)
+	counter[6] ^= byte(ssrc >> 8)
+	counter[7] ^= byte(ssrc)
+	counter[8] ^= byte(rolloverCounter >> 24)
+	counter[9] ^= byte(rolloverCounter >> 16)
+	counter[10] ^= byte(rolloverCounter >> 8)
+	counter[11] ^= byte(rolloverCounter)
+	counter[12] ^= byte(sequenceNumber >> 8)
+	counter[13] ^= byte(sequenceNumber)
 
 	return counter
 }
diff --git a/key_derivation_test.go b/key_derivation_test.go
index 42bf568..a2c7aa5 100644
--- a/key_derivation_test.go
+++ b/key_derivation_test.go
@@ -46,3 +46,19 @@ func TestIndexOverKDR(t *testing.T) {
 	_, err := aesCmKeyDerivation(labelSRTPAuthenticationTag, []byte{}, []byte{}, 1, 0)
 	assert.Error(t, err)
 }
+
+func BenchmarkGenerateCounter(b *testing.B) {
+	masterKey := []byte{0x0d, 0xcd, 0x21, 0x3e, 0x4c, 0xbc, 0xf2, 0x8f, 0x01, 0x7f, 0x69, 0x94, 0x40, 0x1e, 0x28, 0x89}
+	masterSalt := []byte{0x62, 0x77, 0x60, 0x38, 0xc0, 0x6d, 0xc9, 0x41, 0x9f, 0x6d, 0xd9, 0x43, 0x3e, 0x7c}
+
+	s := &srtpSSRCState{ssrc: 4160032510}
+
+	srtpSessionSalt, err := aesCmKeyDerivation(labelSRTPSalt, masterKey, masterSalt, 0, len(masterSalt))
+	assert.NoError(b, err)
+
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		generateCounter(32846, uint32(s.index>>16), s.ssrc, srtpSessionSalt)
+	}
+}
diff --git a/option.go b/option.go
index d6159f1..86ecd8e 100644
--- a/option.go
+++ b/option.go
@@ -8,7 +8,7 @@ import (
 type ContextOption func(*Context) error
 
 // SRTPReplayProtection sets SRTP replay protection window size.
-func SRTPReplayProtection(windowSize uint) ContextOption { // nolint:golint
+func SRTPReplayProtection(windowSize uint) ContextOption { // nolint:revive
 	return func(c *Context) error {
 		c.newSRTPReplayDetector = func() replaydetector.ReplayDetector {
 			return replaydetector.WithWrap(windowSize, maxSequenceNumber)
@@ -28,7 +28,7 @@ func SRTCPReplayProtection(windowSize uint) ContextOption {
 }
 
 // SRTPNoReplayProtection disables SRTP replay protection.
-func SRTPNoReplayProtection() ContextOption { // nolint:golint
+func SRTPNoReplayProtection() ContextOption { // nolint:revive
 	return func(c *Context) error {
 		c.newSRTPReplayDetector = func() replaydetector.ReplayDetector {
 			return &nopReplayDetector{}
diff --git a/protection_profile.go b/protection_profile.go
index 322eca0..71d9ac5 100644
--- a/protection_profile.go
+++ b/protection_profile.go
@@ -9,14 +9,13 @@ type ProtectionProfile uint16
 // See https://www.iana.org/assignments/srtp-protection/srtp-protection.xhtml
 const (
 	ProtectionProfileAes128CmHmacSha1_80 ProtectionProfile = 0x0001
+	ProtectionProfileAes128CmHmacSha1_32 ProtectionProfile = 0x0002
 	ProtectionProfileAeadAes128Gcm       ProtectionProfile = 0x0007
 )
 
 func (p ProtectionProfile) keyLen() (int, error) {
 	switch p {
-	case ProtectionProfileAes128CmHmacSha1_80:
-		fallthrough
-	case ProtectionProfileAeadAes128Gcm:
+	case ProtectionProfileAes128CmHmacSha1_32, ProtectionProfileAes128CmHmacSha1_80, ProtectionProfileAeadAes128Gcm:
 		return 16, nil
 	default:
 		return 0, fmt.Errorf("%w: %#v", errNoSuchSRTPProfile, p)
@@ -25,7 +24,7 @@ func (p ProtectionProfile) keyLen() (int, error) {
 
 func (p ProtectionProfile) saltLen() (int, error) {
 	switch p {
-	case ProtectionProfileAes128CmHmacSha1_80:
+	case ProtectionProfileAes128CmHmacSha1_32, ProtectionProfileAes128CmHmacSha1_80:
 		return 14, nil
 	case ProtectionProfileAeadAes128Gcm:
 		return 12, nil
@@ -34,12 +33,25 @@ func (p ProtectionProfile) saltLen() (int, error) {
 	}
 }
 
-func (p ProtectionProfile) authTagLen() (int, error) {
+func (p ProtectionProfile) rtpAuthTagLen() (int, error) {
 	switch p {
 	case ProtectionProfileAes128CmHmacSha1_80:
-		return (&srtpCipherAesCmHmacSha1{}).authTagLen(), nil
+		return 10, nil
+	case ProtectionProfileAes128CmHmacSha1_32:
+		return 4, nil
+	case ProtectionProfileAeadAes128Gcm:
+		return 0, nil
+	default:
+		return 0, fmt.Errorf("%w: %#v", errNoSuchSRTPProfile, p)
+	}
+}
+
+func (p ProtectionProfile) rtcpAuthTagLen() (int, error) {
+	switch p {
+	case ProtectionProfileAes128CmHmacSha1_32, ProtectionProfileAes128CmHmacSha1_80:
+		return 10, nil
 	case ProtectionProfileAeadAes128Gcm:
-		return (&srtpCipherAeadAesGcm{}).authTagLen(), nil
+		return 0, nil
 	default:
 		return 0, fmt.Errorf("%w: %#v", errNoSuchSRTPProfile, p)
 	}
@@ -47,10 +59,10 @@ func (p ProtectionProfile) authTagLen() (int, error) {
 
 func (p ProtectionProfile) aeadAuthTagLen() (int, error) {
 	switch p {
-	case ProtectionProfileAes128CmHmacSha1_80:
-		return (&srtpCipherAesCmHmacSha1{}).aeadAuthTagLen(), nil
+	case ProtectionProfileAes128CmHmacSha1_32, ProtectionProfileAes128CmHmacSha1_80:
+		return 0, nil
 	case ProtectionProfileAeadAes128Gcm:
-		return (&srtpCipherAeadAesGcm{}).aeadAuthTagLen(), nil
+		return 16, nil
 	default:
 		return 0, fmt.Errorf("%w: %#v", errNoSuchSRTPProfile, p)
 	}
@@ -58,7 +70,7 @@ func (p ProtectionProfile) aeadAuthTagLen() (int, error) {
 
 func (p ProtectionProfile) authKeyLen() (int, error) {
 	switch p {
-	case ProtectionProfileAes128CmHmacSha1_80:
+	case ProtectionProfileAes128CmHmacSha1_32, ProtectionProfileAes128CmHmacSha1_80:
 		return 20, nil
 	case ProtectionProfileAeadAes128Gcm:
 		return 0, nil
diff --git a/session.go b/session.go
index 770c203..7cd8c6f 100644
--- a/session.go
+++ b/session.go
@@ -1,6 +1,7 @@
 package srtp
 
 import (
+	"errors"
 	"io"
 	"net"
 	"sync"
@@ -136,7 +137,7 @@ func (s *session) start(localMasterKey, localMasterSalt, remoteMasterKey, remote
 			var i int
 			i, err = s.nextConn.Read(b)
 			if err != nil {
-				if err != io.EOF {
+				if !errors.Is(err, io.EOF) {
 					s.log.Error(err.Error())
 				}
 				return
diff --git a/session_srtcp.go b/session_srtcp.go
index 2e6e168..8ad13f2 100644
--- a/session_srtcp.go
+++ b/session_srtcp.go
@@ -114,8 +114,11 @@ func (s *SessionSRTCP) write(buf []byte) (int, error) {
 		return 0, errStartedChannelUsedIncorrectly
 	}
 
+	ibuf := bufferpool.Get()
+	defer bufferpool.Put(ibuf)
+
 	s.session.localContextMutex.Lock()
-	encrypted, err := s.localContext.EncryptRTCP(nil, buf, nil)
+	encrypted, err := s.localContext.EncryptRTCP(ibuf.([]byte), buf, nil)
 	s.session.localContextMutex.Unlock()
 
 	if err != nil {
diff --git a/session_srtcp_test.go b/session_srtcp_test.go
index 1fb03f3..b2043d7 100644
--- a/session_srtcp_test.go
+++ b/session_srtcp_test.go
@@ -2,6 +2,7 @@ package srtp
 
 import (
 	"bytes"
+	"errors"
 	"io"
 	"net"
 	"reflect"
@@ -259,7 +260,7 @@ func TestSessionSRTCPReplayProtection(t *testing.T) {
 		for {
 			if ssrc, perr := getSenderSSRC(t, bReadStream); perr == nil {
 				receivedSSRC = append(receivedSSRC, ssrc)
-			} else if perr == io.EOF {
+			} else if errors.Is(perr, io.EOF) {
 				return
 			}
 		}
@@ -301,7 +302,7 @@ func TestSessionSRTCPReplayProtection(t *testing.T) {
 }
 
 func getSenderSSRC(t *testing.T, stream *ReadStreamSRTCP) (ssrc uint32, err error) {
-	authTagSize, err := ProtectionProfileAes128CmHmacSha1_80.authTagLen()
+	authTagSize, err := ProtectionProfileAes128CmHmacSha1_80.rtcpAuthTagLen()
 	if err != nil {
 		return 0, err
 	}
@@ -309,7 +310,7 @@ func getSenderSSRC(t *testing.T, stream *ReadStreamSRTCP) (ssrc uint32, err erro
 	const pliPacketSize = 8
 	readBuffer := make([]byte, pliPacketSize+authTagSize+srtcpIndexSize)
 	n, _, err := stream.ReadRTCP(readBuffer)
-	if err == io.EOF {
+	if errors.Is(err, io.EOF) {
 		return 0, err
 	}
 	if err != nil {
diff --git a/session_srtp.go b/session_srtp.go
index 2de27a9..66ac060 100644
--- a/session_srtp.go
+++ b/session_srtp.go
@@ -2,6 +2,7 @@ package srtp
 
 import (
 	"net"
+	"sync"
 	"time"
 
 	"github.com/pion/logging"
@@ -111,21 +112,41 @@ func (s *SessionSRTP) Close() error {
 func (s *SessionSRTP) write(b []byte) (int, error) {
 	packet := &rtp.Packet{}
 
-	err := packet.Unmarshal(b)
-	if err != nil {
-		return 0, nil
+	if err := packet.Unmarshal(b); err != nil {
+		return 0, err
 	}
 
 	return s.writeRTP(&packet.Header, packet.Payload)
 }
 
+// bufferpool is a global pool of buffers used for encrypted packets in
+// writeRTP below.  Since it's global, buffers can be shared between
+// different sessions, which amortizes the cost of allocating the pool.
+//
+// 1472 is the maximum Ethernet UDP payload.  We give ourselves 20 bytes
+// of slack for any authentication tags, which is more than enough for
+// either CTR or GCM.  If the buffer is too small, no harm, it will just
+// get expanded by growBuffer.
+var bufferpool = sync.Pool{ // nolint:gochecknoglobals
+	New: func() interface{} {
+		return make([]byte, 1492)
+	},
+}
+
 func (s *SessionSRTP) writeRTP(header *rtp.Header, payload []byte) (int, error) {
 	if _, ok := <-s.session.started; ok {
 		return 0, errStartedChannelUsedIncorrectly
 	}
 
+	// encryptRTP will either return our buffer, or, if it is too
+	// small, allocate a new buffer itself.  In either case, it is
+	// safe to put the buffer back into the pool, but only after
+	// nextConn.Write has returned.
+	ibuf := bufferpool.Get()
+	defer bufferpool.Put(ibuf)
+
 	s.session.localContextMutex.Lock()
-	encrypted, err := s.localContext.encryptRTP(nil, header, payload)
+	encrypted, err := s.localContext.encryptRTP(ibuf.([]byte), header, payload)
 	s.session.localContextMutex.Unlock()
 
 	if err != nil {
diff --git a/session_srtp_test.go b/session_srtp_test.go
index 6649d27..a3798ba 100644
--- a/session_srtp_test.go
+++ b/session_srtp_test.go
@@ -2,6 +2,7 @@ package srtp
 
 import (
 	"bytes"
+	"errors"
 	"io"
 	"net"
 	"reflect"
@@ -313,7 +314,7 @@ func TestSessionSRTPReplayProtection(t *testing.T) {
 		for {
 			if seq, perr := assertPayloadSRTP(t, bReadStream, rtpHeaderSize, testPayload); perr == nil {
 				receivedSequenceNumber = append(receivedSequenceNumber, seq)
-			} else if perr == io.EOF {
+			} else if errors.Is(perr, io.EOF) {
 				return
 			}
 		}
@@ -357,7 +358,7 @@ func TestSessionSRTPReplayProtection(t *testing.T) {
 func assertPayloadSRTP(t *testing.T, stream *ReadStreamSRTP, headerSize int, expectedPayload []byte) (seq uint16, err error) {
 	readBuffer := make([]byte, headerSize+len(expectedPayload))
 	n, hdr, err := stream.ReadRTP(readBuffer)
-	if err == io.EOF {
+	if errors.Is(err, io.EOF) {
 		return 0, err
 	}
 	if err != nil {
diff --git a/srtcp.go b/srtcp.go
index dbf5125..d3e387b 100644
--- a/srtcp.go
+++ b/srtcp.go
@@ -11,9 +11,18 @@ const maxSRTCPIndex = 0x7FFFFFFF
 
 func (c *Context) decryptRTCP(dst, encrypted []byte) ([]byte, error) {
 	out := allocateIfMismatch(dst, encrypted)
-	tailOffset := len(encrypted) - (c.cipher.authTagLen() + srtcpIndexSize)
 
-	if tailOffset < 0 {
+	authTagLen, err := c.cipher.rtcpAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	aeadAuthTagLen, err := c.cipher.aeadAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	tailOffset := len(encrypted) - (authTagLen + srtcpIndexSize)
+
+	if tailOffset < aeadAuthTagLen {
 		return nil, fmt.Errorf("%w: %d", errTooShortRTCP, len(encrypted))
 	} else if isEncrypted := encrypted[tailOffset] >> 7; isEncrypted == 0 {
 		return out, nil
@@ -25,10 +34,10 @@ func (c *Context) decryptRTCP(dst, encrypted []byte) ([]byte, error) {
 	s := c.getSRTCPSSRCState(ssrc)
 	markAsValid, ok := s.replayDetector.Check(uint64(index))
 	if !ok {
-		return nil, &errorDuplicated{Proto: "srtcp", SSRC: ssrc, Index: index}
+		return nil, &duplicatedError{Proto: "srtcp", SSRC: ssrc, Index: index}
 	}
 
-	out, err := c.cipher.decryptRTCP(out, encrypted, index, ssrc)
+	out, err = c.cipher.decryptRTCP(out, encrypted, index, ssrc)
 	if err != nil {
 		return nil, err
 	}
diff --git a/srtcp_test.go b/srtcp_test.go
index ffd34bf..f2e870d 100644
--- a/srtcp_test.go
+++ b/srtcp_test.go
@@ -226,7 +226,7 @@ func TestRTCPLifecycleInPlace(t *testing.T) {
 		testCase := testCase
 		t.Run(caseName, func(t *testing.T) {
 			assert := assert.New(t)
-			authTagLen, err := testCase.algo.authTagLen()
+			authTagLen, err := testCase.algo.rtcpAuthTagLen()
 			assert.NoError(err)
 
 			aeadAuthTagLen, err := testCase.algo.aeadAuthTagLen()
@@ -288,11 +288,7 @@ func TestRTCPLifecyclePartialAllocation(t *testing.T) {
 	for caseName, testCase := range rtcpTestCases() {
 		testCase := testCase
 		t.Run(caseName, func(t *testing.T) {
-			if testCase.algo == ProtectionProfileAeadAes128Gcm {
-				t.Skip("FIXME: DecryptRTCP(nil, input, nil) for ProtectionProfileAeadAes128Gcm changes input data")
-			}
 			assert := assert.New(t)
-
 			encryptHeader := &rtcp.Header{}
 			encryptContext, err := CreateContext(testCase.masterKey, testCase.masterSalt, testCase.algo)
 			if err != nil {
@@ -338,7 +334,7 @@ func TestRTCPInvalidAuthTag(t *testing.T) {
 		testCase := testCase
 		t.Run(caseName, func(t *testing.T) {
 			assert := assert.New(t)
-			authTagLen, err := testCase.algo.authTagLen()
+			authTagLen, err := testCase.algo.rtcpAuthTagLen()
 			assert.NoError(err)
 
 			aeadAuthTagLen, err := testCase.algo.aeadAuthTagLen()
@@ -420,7 +416,7 @@ func TestEncryptRTCPSeparation(t *testing.T) {
 			encryptContext, err := CreateContext(testCase.masterKey, testCase.masterSalt, testCase.algo)
 			assert.NoError(err)
 
-			authTagLen, err := testCase.algo.authTagLen()
+			authTagLen, err := testCase.algo.rtcpAuthTagLen()
 			assert.NoError(err)
 
 			decryptContext, err := CreateContext(
@@ -464,3 +460,22 @@ func TestEncryptRTCPSeparation(t *testing.T) {
 		})
 	}
 }
+
+func TestRTCPDecryptShortenedPacket(t *testing.T) {
+	for caseName, testCase := range rtcpTestCasesSingle() {
+		testCase := testCase
+		t.Run(caseName, func(t *testing.T) {
+			pkt := testCase.packets[0]
+			for i := 1; i < len(pkt.encrypted)-1; i++ {
+				packet := pkt.encrypted[:i]
+				decryptContext, err := CreateContext(testCase.masterKey, testCase.masterSalt, testCase.algo)
+				if err != nil {
+					t.Errorf("CreateContext failed: %v", err)
+				}
+				assert.NotPanics(t, func() {
+					_, _ = decryptContext.DecryptRTCP(nil, packet, nil)
+				}, "Panic on length %d/%d", i, len(pkt.encrypted))
+			}
+		})
+	}
+}
diff --git a/srtp.go b/srtp.go
index 2628372..0feaf0f 100644
--- a/srtp.go
+++ b/srtp.go
@@ -10,21 +10,25 @@ func (c *Context) decryptRTP(dst, ciphertext []byte, header *rtp.Header, headerL
 
 	markAsValid, ok := s.replayDetector.Check(uint64(header.SequenceNumber))
 	if !ok {
-		return nil, &errorDuplicated{
+		return nil, &duplicatedError{
 			Proto: "srtp", SSRC: header.SSRC, Index: uint32(header.SequenceNumber),
 		}
 	}
 
-	dst = growBufferSize(dst, len(ciphertext)-c.cipher.authTagLen())
-	roc, updateROC := s.nextRolloverCount(header.SequenceNumber)
+	authTagLen, err := c.cipher.rtpAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	dst = growBufferSize(dst, len(ciphertext)-authTagLen)
+	roc, diff := s.nextRolloverCount(header.SequenceNumber)
 
-	dst, err := c.cipher.decryptRTP(dst, ciphertext, header, headerLen, roc)
+	dst, err = c.cipher.decryptRTP(dst, ciphertext, header, headerLen, roc)
 	if err != nil {
 		return nil, err
 	}
 
 	markAsValid()
-	updateROC()
+	s.updateRolloverCount(header.SequenceNumber, diff)
 	return dst, nil
 }
 
@@ -63,8 +67,8 @@ func (c *Context) EncryptRTP(dst []byte, plaintext []byte, header *rtp.Header) (
 // Similar to above but faster because it can avoid unmarshaling the header and marshaling the payload.
 func (c *Context) encryptRTP(dst []byte, header *rtp.Header, payload []byte) (ciphertext []byte, err error) {
 	s := c.getSRTPSSRCState(header.SSRC)
-	roc, updateROC := s.nextRolloverCount(header.SequenceNumber)
-	updateROC()
+	roc, diff := s.nextRolloverCount(header.SequenceNumber)
+	s.updateRolloverCount(header.SequenceNumber, diff)
 
 	return c.cipher.encryptRTP(dst, header, payload, roc)
 }
diff --git a/srtp_cipher.go b/srtp_cipher.go
index 2cdf325..c272310 100644
--- a/srtp_cipher.go
+++ b/srtp_cipher.go
@@ -7,10 +7,11 @@ import "github.com/pion/rtp"
 type srtpCipher interface {
 	// authTagLen returns auth key length of the cipher.
 	// See the note below.
-	authTagLen() int
+	rtpAuthTagLen() (int, error)
+	rtcpAuthTagLen() (int, error)
 	// aeadAuthTagLen returns AEAD auth key length of the cipher.
 	// See the note below.
-	aeadAuthTagLen() int
+	aeadAuthTagLen() (int, error)
 	getRTCPIndex([]byte) uint32
 
 	encryptRTP([]byte, *rtp.Header, []byte, uint32) ([]byte, error)
diff --git a/srtp_cipher_aead_aes_gcm.go b/srtp_cipher_aead_aes_gcm.go
index d76c404..110b80a 100644
--- a/srtp_cipher_aead_aes_gcm.go
+++ b/srtp_cipher_aead_aes_gcm.go
@@ -13,13 +13,15 @@ const (
 )
 
 type srtpCipherAeadAesGcm struct {
+	ProtectionProfile
+
 	srtpCipher, srtcpCipher cipher.AEAD
 
 	srtpSessionSalt, srtcpSessionSalt []byte
 }
 
-func newSrtpCipherAeadAesGcm(masterKey, masterSalt []byte) (*srtpCipherAeadAesGcm, error) {
-	s := &srtpCipherAeadAesGcm{}
+func newSrtpCipherAeadAesGcm(profile ProtectionProfile, masterKey, masterSalt []byte) (*srtpCipherAeadAesGcm, error) {
+	s := &srtpCipherAeadAesGcm{ProtectionProfile: profile}
 
 	srtpSessionKey, err := aesCmKeyDerivation(labelSRTPEncryption, masterKey, masterSalt, 0, len(masterKey))
 	if err != nil {
@@ -60,33 +62,31 @@ func newSrtpCipherAeadAesGcm(masterKey, masterSalt []byte) (*srtpCipherAeadAesGc
 	return s, nil
 }
 
-func (s *srtpCipherAeadAesGcm) authTagLen() int {
-	return 0
-}
-
-func (s *srtpCipherAeadAesGcm) aeadAuthTagLen() int {
-	return 16
-}
-
 func (s *srtpCipherAeadAesGcm) encryptRTP(dst []byte, header *rtp.Header, payload []byte, roc uint32) (ciphertext []byte, err error) {
 	// Grow the given buffer to fit the output.
-	dst = growBufferSize(dst, header.MarshalSize()+len(payload)+s.aeadAuthTagLen())
+	authTagLen, err := s.aeadAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	dst = growBufferSize(dst, header.MarshalSize()+len(payload)+authTagLen)
 
-	hdr, err := header.Marshal()
+	n, err := header.MarshalTo(dst)
 	if err != nil {
 		return nil, err
 	}
 
 	iv := s.rtpInitializationVector(header, roc)
-	nHdr := len(hdr)
-	s.srtpCipher.Seal(dst[nHdr:nHdr], iv[:], payload, hdr)
-	copy(dst[:nHdr], hdr)
+	s.srtpCipher.Seal(dst[n:n], iv[:], payload, dst[:n])
 	return dst, nil
 }
 
 func (s *srtpCipherAeadAesGcm) decryptRTP(dst, ciphertext []byte, header *rtp.Header, headerLen int, roc uint32) ([]byte, error) {
 	// Grow the given buffer to fit the output.
-	nDst := len(ciphertext) - s.aeadAuthTagLen()
+	authTagLen, err := s.aeadAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	nDst := len(ciphertext) - authTagLen
 	if nDst < 0 {
 		// Size of ciphertext is shorter than AEAD auth tag len.
 		return nil, errFailedToVerifyAuthTag
@@ -106,7 +106,11 @@ func (s *srtpCipherAeadAesGcm) decryptRTP(dst, ciphertext []byte, header *rtp.He
 }
 
 func (s *srtpCipherAeadAesGcm) encryptRTCP(dst, decrypted []byte, srtcpIndex uint32, ssrc uint32) ([]byte, error) {
-	aadPos := len(decrypted) + s.aeadAuthTagLen()
+	authTagLen, err := s.aeadAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	aadPos := len(decrypted) + authTagLen
 	// Grow the given buffer to fit the output.
 	dst = growBufferSize(dst, aadPos+srtcpIndexSize)
 
@@ -123,7 +127,11 @@ func (s *srtpCipherAeadAesGcm) encryptRTCP(dst, decrypted []byte, srtcpIndex uin
 func (s *srtpCipherAeadAesGcm) decryptRTCP(dst, encrypted []byte, srtcpIndex, ssrc uint32) ([]byte, error) {
 	aadPos := len(encrypted) - srtcpIndexSize
 	// Grow the given buffer to fit the output.
-	nDst := aadPos - s.aeadAuthTagLen()
+	authTagLen, err := s.aeadAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	nDst := aadPos - authTagLen
 	if nDst < 0 {
 		// Size of ciphertext is shorter than AEAD auth tag len.
 		return nil, errFailedToVerifyAuthTag
diff --git a/srtp_cipher_aes_cm_hmac_sha1.go b/srtp_cipher_aes_cm_hmac_sha1.go
index 8ca7317..0e3af50 100644
--- a/srtp_cipher_aes_cm_hmac_sha1.go
+++ b/srtp_cipher_aes_cm_hmac_sha1.go
@@ -13,6 +13,8 @@ import ( //nolint:gci
 )
 
 type srtpCipherAesCmHmacSha1 struct {
+	ProtectionProfile
+
 	srtpSessionSalt []byte
 	srtpSessionAuth hash.Hash
 	srtpBlock       cipher.Block
@@ -22,8 +24,8 @@ type srtpCipherAesCmHmacSha1 struct {
 	srtcpBlock       cipher.Block
 }
 
-func newSrtpCipherAesCmHmacSha1(masterKey, masterSalt []byte) (*srtpCipherAesCmHmacSha1, error) {
-	s := &srtpCipherAesCmHmacSha1{}
+func newSrtpCipherAesCmHmacSha1(profile ProtectionProfile, masterKey, masterSalt []byte) (*srtpCipherAesCmHmacSha1, error) {
+	s := &srtpCipherAesCmHmacSha1{ProtectionProfile: profile}
 	srtpSessionKey, err := aesCmKeyDerivation(labelSRTPEncryption, masterKey, masterSalt, 0, len(masterKey))
 	if err != nil {
 		return nil, err
@@ -44,7 +46,7 @@ func newSrtpCipherAesCmHmacSha1(masterKey, masterSalt []byte) (*srtpCipherAesCmH
 		return nil, err
 	}
 
-	authKeyLen, err := ProtectionProfileAes128CmHmacSha1_80.authKeyLen()
+	authKeyLen, err := profile.authKeyLen()
 	if err != nil {
 		return nil, err
 	}
@@ -64,17 +66,13 @@ func newSrtpCipherAesCmHmacSha1(masterKey, masterSalt []byte) (*srtpCipherAesCmH
 	return s, nil
 }
 
-func (s *srtpCipherAesCmHmacSha1) authTagLen() int {
-	return 10
-}
-
-func (s *srtpCipherAesCmHmacSha1) aeadAuthTagLen() int {
-	return 0
-}
-
 func (s *srtpCipherAesCmHmacSha1) encryptRTP(dst []byte, header *rtp.Header, payload []byte, roc uint32) (ciphertext []byte, err error) {
 	// Grow the given buffer to fit the output.
-	dst = growBufferSize(dst, header.MarshalSize()+len(payload)+s.authTagLen())
+	authTagLen, err := s.rtpAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	dst = growBufferSize(dst, header.MarshalSize()+len(payload)+authTagLen)
 
 	// Copy the header unencrypted.
 	n, err := header.MarshalTo(dst)
@@ -84,8 +82,9 @@ func (s *srtpCipherAesCmHmacSha1) encryptRTP(dst []byte, header *rtp.Header, pay
 
 	// Encrypt the payload
 	counter := generateCounter(header.SequenceNumber, roc, header.SSRC, s.srtpSessionSalt)
-	stream := cipher.NewCTR(s.srtpBlock, counter[:])
-	stream.XORKeyStream(dst[n:], payload)
+	if err = xorBytesCTR(s.srtpBlock, counter[:], dst[n:], payload); err != nil {
+		return nil, err
+	}
 	n += len(payload)
 
 	// Generate the auth tag.
@@ -102,8 +101,12 @@ func (s *srtpCipherAesCmHmacSha1) encryptRTP(dst []byte, header *rtp.Header, pay
 
 func (s *srtpCipherAesCmHmacSha1) decryptRTP(dst, ciphertext []byte, header *rtp.Header, headerLen int, roc uint32) ([]byte, error) {
 	// Split the auth tag and the cipher text into two parts.
-	actualTag := ciphertext[len(ciphertext)-s.authTagLen():]
-	ciphertext = ciphertext[:len(ciphertext)-s.authTagLen()]
+	authTagLen, err := s.rtpAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	actualTag := ciphertext[len(ciphertext)-authTagLen:]
+	ciphertext = ciphertext[:len(ciphertext)-authTagLen]
 
 	// Generate the auth tag we expect to see from the ciphertext.
 	expectedTag, err := s.generateSrtpAuthTag(ciphertext, roc)
@@ -122,9 +125,10 @@ func (s *srtpCipherAesCmHmacSha1) decryptRTP(dst, ciphertext []byte, header *rtp
 
 	// Decrypt the ciphertext for the payload.
 	counter := generateCounter(header.SequenceNumber, roc, header.SSRC, s.srtpSessionSalt)
-	stream := cipher.NewCTR(s.srtpBlock, counter[:])
-	stream.XORKeyStream(dst[headerLen:], ciphertext[headerLen:])
-	return dst, nil
+	err = xorBytesCTR(
+		s.srtpBlock, counter[:], dst[headerLen:], ciphertext[headerLen:],
+	)
+	return dst, err
 }
 
 func (s *srtpCipherAesCmHmacSha1) encryptRTCP(dst, decrypted []byte, srtcpIndex uint32, ssrc uint32) ([]byte, error) {
@@ -132,8 +136,9 @@ func (s *srtpCipherAesCmHmacSha1) encryptRTCP(dst, decrypted []byte, srtcpIndex
 
 	// Encrypt everything after header
 	counter := generateCounter(uint16(srtcpIndex&0xffff), srtcpIndex>>16, ssrc, s.srtcpSessionSalt)
-	stream := cipher.NewCTR(s.srtcpBlock, counter[:])
-	stream.XORKeyStream(dst[8:], dst[8:])
+	if err := xorBytesCTR(s.srtcpBlock, counter[:], dst[8:], dst[8:]); err != nil {
+		return nil, err
+	}
 
 	// Add SRTCP Index and set Encryption bit
 	dst = append(dst, make([]byte, 4)...)
@@ -148,24 +153,27 @@ func (s *srtpCipherAesCmHmacSha1) encryptRTCP(dst, decrypted []byte, srtcpIndex
 }
 
 func (s *srtpCipherAesCmHmacSha1) decryptRTCP(out, encrypted []byte, index, ssrc uint32) ([]byte, error) {
-	tailOffset := len(encrypted) - (s.authTagLen() + srtcpIndexSize)
+	authTagLen, err := s.rtcpAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	tailOffset := len(encrypted) - (authTagLen + srtcpIndexSize)
 	out = out[0:tailOffset]
 
-	expectedTag, err := s.generateSrtcpAuthTag(encrypted[:len(encrypted)-s.authTagLen()])
+	expectedTag, err := s.generateSrtcpAuthTag(encrypted[:len(encrypted)-authTagLen])
 	if err != nil {
 		return nil, err
 	}
 
-	actualTag := encrypted[len(encrypted)-s.authTagLen():]
+	actualTag := encrypted[len(encrypted)-authTagLen:]
 	if subtle.ConstantTimeCompare(actualTag, expectedTag) != 1 {
 		return nil, errFailedToVerifyAuthTag
 	}
 
 	counter := generateCounter(uint16(index&0xffff), index>>16, ssrc, s.srtcpSessionSalt)
-	stream := cipher.NewCTR(s.srtcpBlock, counter[:])
-	stream.XORKeyStream(out[8:], out[8:])
+	err = xorBytesCTR(s.srtcpBlock, counter[:], out[8:], out[8:])
 
-	return out, nil
+	return out, err
 }
 
 func (s *srtpCipherAesCmHmacSha1) generateSrtpAuthTag(buf []byte, roc uint32) ([]byte, error) {
@@ -198,8 +206,12 @@ func (s *srtpCipherAesCmHmacSha1) generateSrtpAuthTag(buf []byte, roc uint32) ([
 		return nil, err
 	}
 
-	// Truncate the hash to the first 10 bytes.
-	return s.srtpSessionAuth.Sum(nil)[0:s.authTagLen()], nil
+	// Truncate the hash to the size indicated by the profile
+	authTagLen, err := s.rtpAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
+	return s.srtpSessionAuth.Sum(nil)[0:authTagLen], nil
 }
 
 func (s *srtpCipherAesCmHmacSha1) generateSrtcpAuthTag(buf []byte) ([]byte, error) {
@@ -219,12 +231,17 @@ func (s *srtpCipherAesCmHmacSha1) generateSrtcpAuthTag(buf []byte) ([]byte, erro
 	if _, err := s.srtcpSessionAuth.Write(buf); err != nil {
 		return nil, err
 	}
+	authTagLen, err := s.rtcpAuthTagLen()
+	if err != nil {
+		return nil, err
+	}
 
-	return s.srtcpSessionAuth.Sum(nil)[0:s.authTagLen()], nil
+	return s.srtcpSessionAuth.Sum(nil)[0:authTagLen], nil
 }
 
 func (s *srtpCipherAesCmHmacSha1) getRTCPIndex(in []byte) uint32 {
-	tailOffset := len(in) - (s.authTagLen() + srtcpIndexSize)
+	authTagLen, _ := s.rtcpAuthTagLen()
+	tailOffset := len(in) - (authTagLen + srtcpIndexSize)
 	srtcpIndexBuffer := in[tailOffset : tailOffset+srtcpIndexSize]
 	return binary.BigEndian.Uint32(srtcpIndexBuffer) &^ (1 << 31)
 }
diff --git a/srtp_test.go b/srtp_test.go
index 0f9236f..8333b48 100644
--- a/srtp_test.go
+++ b/srtp_test.go
@@ -10,35 +10,53 @@ import (
 )
 
 const (
-	cipherContextAlgo = ProtectionProfileAes128CmHmacSha1_80
-	defaultSsrc       = 0
+	profileCTR  = ProtectionProfileAes128CmHmacSha1_80
+	profileGCM  = ProtectionProfileAeadAes128Gcm
+	defaultSsrc = 0
 )
 
 type rtpTestCase struct {
 	sequenceNumber uint16
-	encrypted      []byte
+	encryptedCTR   []byte
+	encryptedGCM   []byte
 }
 
-func TestKeyLen(t *testing.T) {
-	keyLen, err := cipherContextAlgo.keyLen()
+func (tc rtpTestCase) encrypted(profile ProtectionProfile) []byte {
+	switch profile {
+	case profileCTR:
+		return tc.encryptedCTR
+	case profileGCM:
+		return tc.encryptedGCM
+	default:
+		panic("unknown profile")
+	}
+}
+
+func testKeyLen(t *testing.T, profile ProtectionProfile) {
+	keyLen, err := profile.keyLen()
 	assert.NoError(t, err)
 
-	saltLen, err := cipherContextAlgo.saltLen()
+	saltLen, err := profile.saltLen()
 	assert.NoError(t, err)
 
-	if _, err := CreateContext([]byte{}, make([]byte, saltLen), cipherContextAlgo); err == nil {
+	if _, err := CreateContext([]byte{}, make([]byte, saltLen), profile); err == nil {
 		t.Errorf("CreateContext accepted a 0 length key")
 	}
 
-	if _, err := CreateContext(make([]byte, keyLen), []byte{}, cipherContextAlgo); err == nil {
+	if _, err := CreateContext(make([]byte, keyLen), []byte{}, profile); err == nil {
 		t.Errorf("CreateContext accepted a 0 length salt")
 	}
 
-	if _, err := CreateContext(make([]byte, keyLen), make([]byte, saltLen), cipherContextAlgo); err != nil {
+	if _, err := CreateContext(make([]byte, keyLen), make([]byte, saltLen), profile); err != nil {
 		t.Errorf("CreateContext failed with a valid length key and salt: %v", err)
 	}
 }
 
+func TestKeyLen(t *testing.T) {
+	t.Run("CTR", func(t *testing.T) { testKeyLen(t, profileCTR) })
+	t.Run("GCM", func(t *testing.T) { testKeyLen(t, profileGCM) })
+}
+
 func TestValidPacketCounter(t *testing.T) {
 	masterKey := []byte{0x0d, 0xcd, 0x21, 0x3e, 0x4c, 0xbc, 0xf2, 0x8f, 0x01, 0x7f, 0x69, 0x94, 0x40, 0x1e, 0x28, 0x89}
 	masterSalt := []byte{0x62, 0x77, 0x60, 0x38, 0xc0, 0x6d, 0xc9, 0x41, 0x9f, 0x6d, 0xd9, 0x43, 0x3e, 0x7c}
@@ -58,11 +76,11 @@ func TestRolloverCount(t *testing.T) {
 	s := &srtpSSRCState{ssrc: defaultSsrc}
 
 	// Set initial seqnum
-	roc, update := s.nextRolloverCount(65530)
+	roc, diff := s.nextRolloverCount(65530)
 	if roc != 0 {
 		t.Errorf("Initial rolloverCounter must be 0")
 	}
-	update()
+	s.updateRolloverCount(65530, diff)
 
 	// Invalid packets never update ROC
 	_, _ = s.nextRolloverCount(0)
@@ -72,73 +90,84 @@ func TestRolloverCount(t *testing.T) {
 	_, _ = s.nextRolloverCount(0)
 
 	// We rolled over to 0
-	roc, update = s.nextRolloverCount(0)
+	roc, diff = s.nextRolloverCount(0)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was not updated after it crossed 0")
 	}
-	update()
+	s.updateRolloverCount(0, diff)
 
-	roc, update = s.nextRolloverCount(65530)
+	roc, diff = s.nextRolloverCount(65530)
 	if roc != 0 {
 		t.Errorf("rolloverCounter was not updated when it rolled back, failed to handle out of order")
 	}
-	update()
+	s.updateRolloverCount(65530, diff)
 
-	roc, update = s.nextRolloverCount(5)
+	roc, diff = s.nextRolloverCount(5)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was not updated when it rolled over initial, to handle out of order")
 	}
-	update()
+	s.updateRolloverCount(5, diff)
 
-	_, update = s.nextRolloverCount(6)
-	update()
-	_, update = s.nextRolloverCount(7)
-	update()
-	roc, update = s.nextRolloverCount(8)
+	_, diff = s.nextRolloverCount(6)
+	s.updateRolloverCount(6, diff)
+	_, diff = s.nextRolloverCount(7)
+	s.updateRolloverCount(7, diff)
+	roc, diff = s.nextRolloverCount(8)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was improperly updated for non-significant packets")
 	}
-	update()
+	s.updateRolloverCount(8, diff)
 
 	// valid packets never update ROC
-	roc, update = s.nextRolloverCount(0x4000)
+	roc, diff = s.nextRolloverCount(0x4000)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was improperly updated for non-significant packets")
 	}
-	update()
-	roc, update = s.nextRolloverCount(0x8000)
+	s.updateRolloverCount(0x4000, diff)
+	roc, diff = s.nextRolloverCount(0x8000)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was improperly updated for non-significant packets")
 	}
-	update()
-	roc, update = s.nextRolloverCount(0xFFFF)
+	s.updateRolloverCount(0x8000, diff)
+	roc, diff = s.nextRolloverCount(0xFFFF)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was improperly updated for non-significant packets")
 	}
-	update()
+	s.updateRolloverCount(0xFFFF, diff)
 	roc, _ = s.nextRolloverCount(0)
 	if roc != 2 {
 		t.Errorf("rolloverCounter must be incremented after wrapping, got %d", roc)
 	}
 }
 
-func buildTestContext(opts ...ContextOption) (*Context, error) {
+func buildTestContext(profile ProtectionProfile, opts ...ContextOption) (*Context, error) {
+	keyLen, err := profile.keyLen()
+	if err != nil {
+		return nil, err
+	}
+	saltLen, err := profile.saltLen()
+	if err != nil {
+		return nil, err
+	}
+
 	masterKey := []byte{0x0d, 0xcd, 0x21, 0x3e, 0x4c, 0xbc, 0xf2, 0x8f, 0x01, 0x7f, 0x69, 0x94, 0x40, 0x1e, 0x28, 0x89}
+	masterKey = masterKey[:keyLen]
 	masterSalt := []byte{0x62, 0x77, 0x60, 0x38, 0xc0, 0x6d, 0xc9, 0x41, 0x9f, 0x6d, 0xd9, 0x43, 0x3e, 0x7c}
+	masterSalt = masterSalt[:saltLen]
 
-	return CreateContext(masterKey, masterSalt, cipherContextAlgo, opts...)
+	return CreateContext(masterKey, masterSalt, profile, opts...)
 }
 
 func TestRTPInvalidAuth(t *testing.T) {
 	masterKey := []byte{0x0d, 0xcd, 0x21, 0x3e, 0x4c, 0xbc, 0xf2, 0x8f, 0x01, 0x7f, 0x69, 0x94, 0x40, 0x1e, 0x28, 0x89}
 	invalidSalt := []byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00}
 
-	encryptContext, err := buildTestContext()
+	encryptContext, err := buildTestContext(profileCTR)
 	if err != nil {
 		t.Fatal(err)
 	}
 
-	invalidContext, err := CreateContext(masterKey, invalidSalt, cipherContextAlgo)
+	invalidContext, err := CreateContext(masterKey, invalidSalt, profileCTR)
 	if err != nil {
 		t.Errorf("CreateContext failed: %v", err)
 	}
@@ -167,44 +196,50 @@ func rtpTestCases() []rtpTestCase {
 	return []rtpTestCase{
 		{
 			sequenceNumber: 5000,
-			encrypted:      []byte{0x6d, 0xd3, 0x7e, 0xd5, 0x99, 0xb7, 0x2d, 0x28, 0xb1, 0xf3, 0xa1, 0xf0, 0xc, 0xfb, 0xfd, 0x8},
+			encryptedCTR:   []byte{0x6d, 0xd3, 0x7e, 0xd5, 0x99, 0xb7, 0x2d, 0x28, 0xb1, 0xf3, 0xa1, 0xf0, 0xc, 0xfb, 0xfd, 0x8},
+			encryptedGCM:   []byte{0x05, 0x39, 0x62, 0xbb, 0x50, 0x2a, 0x08, 0x19, 0xc7, 0xcc, 0xc9, 0x24, 0xb8, 0xd9, 0x7a, 0xe5, 0xad, 0x99, 0x06, 0xc7, 0x3b, 0},
 		},
 		{
 			sequenceNumber: 5001,
-			encrypted:      []byte{0xda, 0x47, 0xb, 0x2a, 0x74, 0x53, 0x65, 0xbd, 0x2f, 0xeb, 0xdc, 0x4b, 0x6d, 0x23, 0xf3, 0xde},
+			encryptedCTR:   []byte{0xda, 0x47, 0xb, 0x2a, 0x74, 0x53, 0x65, 0xbd, 0x2f, 0xeb, 0xdc, 0x4b, 0x6d, 0x23, 0xf3, 0xde},
+			encryptedGCM:   []byte{0xb0, 0xbc, 0xfc, 0xb0, 0x15, 0x2c, 0xa0, 0x15, 0xb5, 0xa8, 0xcd, 0x0d, 0x65, 0xfa, 0x98, 0xb3, 0x09, 0xb1, 0xf8, 0x4b, 0x1c, 0xfa},
 		},
 		{
 			sequenceNumber: 5002,
-			encrypted:      []byte{0x6e, 0xa7, 0x69, 0x8d, 0x24, 0x6d, 0xdc, 0xbf, 0xec, 0x2, 0x1c, 0xd1, 0x60, 0x76, 0xc1, 0xe},
+			encryptedCTR:   []byte{0x6e, 0xa7, 0x69, 0x8d, 0x24, 0x6d, 0xdc, 0xbf, 0xec, 0x2, 0x1c, 0xd1, 0x60, 0x76, 0xc1, 0xe},
+			encryptedGCM:   []byte{0x5e, 0x20, 0x6a, 0xbf, 0x58, 0x7e, 0x24, 0xc0, 0x15, 0x94, 0x7a, 0xe2, 0x49, 0x25, 0xd4, 0xd4, 0x08, 0xe2, 0xf1, 0x47, 0x7a, 0x33},
 		},
 		{
 			sequenceNumber: 5003,
-			encrypted:      []byte{0x24, 0x7e, 0x96, 0xc8, 0x7d, 0x33, 0xa2, 0x92, 0x8d, 0x13, 0x8d, 0xe0, 0x76, 0x9f, 0x8, 0xdc},
+			encryptedCTR:   []byte{0x24, 0x7e, 0x96, 0xc8, 0x7d, 0x33, 0xa2, 0x92, 0x8d, 0x13, 0x8d, 0xe0, 0x76, 0x9f, 0x8, 0xdc},
+			encryptedGCM:   []byte{0xb0, 0x63, 0x14, 0xe7, 0xd2, 0x29, 0xca, 0x92, 0x8c, 0x97, 0x25, 0xd2, 0x50, 0x69, 0x6e, 0x1b, 0x04, 0xb9, 0x37, 0xa5, 0xa1, 0xc5},
 		},
 		{
 			sequenceNumber: 5004,
-			encrypted:      []byte{0x75, 0x43, 0x28, 0xe4, 0x3a, 0x77, 0x59, 0x9b, 0x2e, 0xdf, 0x7b, 0x12, 0x68, 0xb, 0x57, 0x49},
+			encryptedCTR:   []byte{0x75, 0x43, 0x28, 0xe4, 0x3a, 0x77, 0x59, 0x9b, 0x2e, 0xdf, 0x7b, 0x12, 0x68, 0xb, 0x57, 0x49},
+			encryptedGCM:   []byte{0xb2, 0x4f, 0x19, 0x53, 0x79, 0x8a, 0x9b, 0x9e, 0xe5, 0x22, 0x93, 0x14, 0x50, 0x8a, 0x8c, 0xd5, 0xfc, 0x61, 0xbf, 0x95, 0xd1, 0xfb},
 		},
 		{
 			sequenceNumber: 65535, // upper boundary
-			encrypted:      []byte{0xaf, 0xf7, 0xc2, 0x70, 0x37, 0x20, 0x83, 0x9c, 0x2c, 0x63, 0x85, 0x15, 0xe, 0x44, 0xca, 0x36},
+			encryptedCTR:   []byte{0xaf, 0xf7, 0xc2, 0x70, 0x37, 0x20, 0x83, 0x9c, 0x2c, 0x63, 0x85, 0x15, 0xe, 0x44, 0xca, 0x36},
+			encryptedGCM:   []byte{0x40, 0x44, 0x6c, 0xd1, 0x33, 0x5f, 0xca, 0x9b, 0x2e, 0xa3, 0xe5, 0x03, 0xd7, 0x82, 0x36, 0xd8, 0xb7, 0xe8, 0x97, 0x3c, 0xe6, 0xb6},
 		},
 	}
 }
 
-func TestRTPLifecyleNewAlloc(t *testing.T) {
+func testRTPLifecyleNewAlloc(t *testing.T, profile ProtectionProfile) {
 	assert := assert.New(t)
 
-	authTagLen, err := ProtectionProfileAes128CmHmacSha1_80.authTagLen()
+	authTagLen, err := profile.rtpAuthTagLen()
 	assert.NoError(err)
 
 	for _, testCase := range rtpTestCases() {
-		encryptContext, err := buildTestContext()
+		encryptContext, err := buildTestContext(profile)
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		decryptContext, err := buildTestContext()
+		decryptContext, err := buildTestContext(profile)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -215,7 +250,7 @@ func TestRTPLifecyleNewAlloc(t *testing.T) {
 			t.Fatal(err)
 		}
 
-		encryptedPkt := &rtp.Packet{Payload: testCase.encrypted, Header: rtp.Header{SequenceNumber: testCase.sequenceNumber}}
+		encryptedPkt := &rtp.Packet{Payload: testCase.encrypted(profile), Header: rtp.Header{SequenceNumber: testCase.sequenceNumber}}
 		encryptedRaw, err := encryptedPkt.Marshal()
 		if err != nil {
 			t.Fatal(err)
@@ -238,16 +273,21 @@ func TestRTPLifecyleNewAlloc(t *testing.T) {
 	}
 }
 
-func TestRTPLifecyleInPlace(t *testing.T) {
+func TestRTPLifecycleNewAlloc(t *testing.T) {
+	t.Run("CTR", func(t *testing.T) { testRTPLifecyleNewAlloc(t, profileCTR) })
+	t.Run("GCM", func(t *testing.T) { testRTPLifecyleNewAlloc(t, profileGCM) })
+}
+
+func testRTPLifecyleInPlace(t *testing.T, profile ProtectionProfile) {
 	assert := assert.New(t)
 
 	for _, testCase := range rtpTestCases() {
-		encryptContext, err := buildTestContext()
+		encryptContext, err := buildTestContext(profile)
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		decryptContext, err := buildTestContext()
+		decryptContext, err := buildTestContext(profile)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -260,14 +300,18 @@ func TestRTPLifecyleInPlace(t *testing.T) {
 		}
 
 		encryptHeader := &rtp.Header{}
-		encryptedPkt := &rtp.Packet{Payload: testCase.encrypted, Header: rtp.Header{SequenceNumber: testCase.sequenceNumber}}
+		encryptedPkt := &rtp.Packet{Payload: testCase.encrypted(profile), Header: rtp.Header{SequenceNumber: testCase.sequenceNumber}}
 		encryptedRaw, err := encryptedPkt.Marshal()
 		if err != nil {
 			t.Fatal(err)
 		}
 
 		// Copy packet, asserts that everything was done in place
-		encryptInput := make([]byte, len(decryptedRaw), len(decryptedRaw)+10)
+		slack := 10
+		if profile == profileGCM {
+			slack = 16
+		}
+		encryptInput := make([]byte, len(decryptedRaw), len(decryptedRaw)+slack)
 		copy(encryptInput, decryptedRaw)
 
 		actualEncrypted, err := encryptContext.EncryptRTP(encryptInput, encryptInput, encryptHeader)
@@ -275,9 +319,9 @@ func TestRTPLifecyleInPlace(t *testing.T) {
 		case err != nil:
 			t.Fatal(err)
 		case &encryptInput[0] != &actualEncrypted[0]:
-			t.Fatal("EncryptRTP failed to encrypt in place")
+			t.Errorf("EncryptRTP failed to encrypt in place")
 		case encryptHeader.SequenceNumber != testCase.sequenceNumber:
-			t.Fatal("EncryptRTP failed to populate input rtp.Header")
+			t.Errorf("EncryptRTP failed to populate input rtp.Header")
 		}
 		assert.Equalf(actualEncrypted, encryptedRaw, "RTP packet with SeqNum invalid encryption: %d", testCase.sequenceNumber)
 
@@ -290,24 +334,31 @@ func TestRTPLifecyleInPlace(t *testing.T) {
 		case err != nil:
 			t.Fatal(err)
 		case &decryptInput[0] != &actualDecrypted[0]:
-			t.Fatal("DecryptRTP failed to decrypt in place")
+			t.Errorf("DecryptRTP failed to decrypt in place")
 		case decryptHeader.SequenceNumber != testCase.sequenceNumber:
-			t.Fatal("DecryptRTP failed to populate input rtp.Header")
+			t.Errorf("DecryptRTP failed to populate input rtp.Header")
 		}
 		assert.Equalf(actualDecrypted, decryptedRaw, "RTP packet with SeqNum invalid decryption: %d", testCase.sequenceNumber)
 	}
 }
 
-func TestRTPReplayProtection(t *testing.T) {
+func TestRTPLifecycleInPlace(t *testing.T) {
+	t.Run("CTR", func(t *testing.T) { testRTPLifecyleInPlace(t, profileCTR) })
+	t.Run("GCM", func(t *testing.T) { testRTPLifecyleInPlace(t, profileGCM) })
+}
+
+func testRTPReplayProtection(t *testing.T, profile ProtectionProfile) {
 	assert := assert.New(t)
 
 	for _, testCase := range rtpTestCases() {
-		encryptContext, err := buildTestContext()
+		encryptContext, err := buildTestContext(profile)
 		if err != nil {
 			t.Fatal(err)
 		}
 
-		decryptContext, err := buildTestContext(SRTPReplayProtection(64))
+		decryptContext, err := buildTestContext(
+			profile, SRTPReplayProtection(64),
+		)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -320,14 +371,18 @@ func TestRTPReplayProtection(t *testing.T) {
 		}
 
 		encryptHeader := &rtp.Header{}
-		encryptedPkt := &rtp.Packet{Payload: testCase.encrypted, Header: rtp.Header{SequenceNumber: testCase.sequenceNumber}}
+		encryptedPkt := &rtp.Packet{Payload: testCase.encrypted(profile), Header: rtp.Header{SequenceNumber: testCase.sequenceNumber}}
 		encryptedRaw, err := encryptedPkt.Marshal()
 		if err != nil {
 			t.Fatal(err)
 		}
 
 		// Copy packet, asserts that everything was done in place
-		encryptInput := make([]byte, len(decryptedRaw), len(decryptedRaw)+10)
+		slack := 10
+		if profile == profileGCM {
+			slack = 16
+		}
+		encryptInput := make([]byte, len(decryptedRaw), len(decryptedRaw)+slack)
 		copy(encryptInput, decryptedRaw)
 
 		actualEncrypted, err := encryptContext.EncryptRTP(encryptInput, encryptInput, encryptHeader)
@@ -335,7 +390,7 @@ func TestRTPReplayProtection(t *testing.T) {
 		case err != nil:
 			t.Fatal(err)
 		case &encryptInput[0] != &actualEncrypted[0]:
-			t.Fatal("EncryptRTP failed to encrypt in place")
+			t.Errorf("EncryptRTP failed to encrypt in place")
 		case encryptHeader.SequenceNumber != testCase.sequenceNumber:
 			t.Fatal("EncryptRTP failed to populate input rtp.Header")
 		}
@@ -350,9 +405,9 @@ func TestRTPReplayProtection(t *testing.T) {
 		case err != nil:
 			t.Fatal(err)
 		case &decryptInput[0] != &actualDecrypted[0]:
-			t.Fatal("DecryptRTP failed to decrypt in place")
+			t.Errorf("DecryptRTP failed to decrypt in place")
 		case decryptHeader.SequenceNumber != testCase.sequenceNumber:
-			t.Fatal("DecryptRTP failed to populate input rtp.Header")
+			t.Errorf("DecryptRTP failed to populate input rtp.Header")
 		}
 		assert.Equalf(actualDecrypted, decryptedRaw, "RTP packet with SeqNum invalid decryption: %d", testCase.sequenceNumber)
 
@@ -363,18 +418,24 @@ func TestRTPReplayProtection(t *testing.T) {
 	}
 }
 
-func BenchmarkEncryptRTP(b *testing.B) {
-	encryptContext, err := buildTestContext()
+func TestRTPReplayProtection(t *testing.T) {
+	t.Run("CTR", func(t *testing.T) { testRTPReplayProtection(t, profileCTR) })
+	t.Run("GCM", func(t *testing.T) { testRTPReplayProtection(t, profileGCM) })
+}
+
+func benchmarkEncryptRTP(b *testing.B, profile ProtectionProfile, size int) {
+	encryptContext, err := buildTestContext(profile)
 	if err != nil {
 		b.Fatal(err)
 	}
 
-	pkt := &rtp.Packet{Payload: make([]byte, 100)}
+	pkt := &rtp.Packet{Payload: make([]byte, size)}
 	pktRaw, err := pkt.Marshal()
 	if err != nil {
 		b.Fatal(err)
 	}
 
+	b.SetBytes(int64(len(pktRaw)))
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
@@ -385,13 +446,28 @@ func BenchmarkEncryptRTP(b *testing.B) {
 	}
 }
 
-func BenchmarkEncryptRTPInPlace(b *testing.B) {
-	encryptContext, err := buildTestContext()
+func BenchmarkEncryptRTP(b *testing.B) {
+	b.Run("CTR-100", func(b *testing.B) {
+		benchmarkEncryptRTP(b, profileCTR, 100)
+	})
+	b.Run("CTR-1000", func(b *testing.B) {
+		benchmarkEncryptRTP(b, profileCTR, 1000)
+	})
+	b.Run("GCM-100", func(b *testing.B) {
+		benchmarkEncryptRTP(b, profileGCM, 100)
+	})
+	b.Run("GCM-1000", func(b *testing.B) {
+		benchmarkEncryptRTP(b, profileGCM, 1000)
+	})
+}
+
+func benchmarkEncryptRTPInPlace(b *testing.B, profile ProtectionProfile, size int) {
+	encryptContext, err := buildTestContext(profile)
 	if err != nil {
 		b.Fatal(err)
 	}
 
-	pkt := &rtp.Packet{Payload: make([]byte, 100)}
+	pkt := &rtp.Packet{Payload: make([]byte, size)}
 	pktRaw, err := pkt.Marshal()
 	if err != nil {
 		b.Fatal(err)
@@ -399,6 +475,7 @@ func BenchmarkEncryptRTPInPlace(b *testing.B) {
 
 	buf := make([]byte, 0, len(pktRaw)+10)
 
+	b.SetBytes(int64(len(pktRaw)))
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
@@ -409,9 +486,24 @@ func BenchmarkEncryptRTPInPlace(b *testing.B) {
 	}
 }
 
-func BenchmarkDecryptRTP(b *testing.B) {
+func BenchmarkEncryptRTPInPlace(b *testing.B) {
+	b.Run("CTR-100", func(b *testing.B) {
+		benchmarkEncryptRTPInPlace(b, profileCTR, 100)
+	})
+	b.Run("CTR-1000", func(b *testing.B) {
+		benchmarkEncryptRTPInPlace(b, profileCTR, 1000)
+	})
+	b.Run("GCM-100", func(b *testing.B) {
+		benchmarkEncryptRTPInPlace(b, profileGCM, 100)
+	})
+	b.Run("GCM-1000", func(b *testing.B) {
+		benchmarkEncryptRTPInPlace(b, profileGCM, 1000)
+	})
+}
+
+func benchmarkDecryptRTP(b *testing.B, profile ProtectionProfile) {
 	sequenceNumber := uint16(5000)
-	encrypted := []byte{0x6d, 0xd3, 0x7e, 0xd5, 0x99, 0xb7, 0x2d, 0x28, 0xb1, 0xf3, 0xa1, 0xf0, 0xc, 0xfb, 0xfd, 0x8}
+	encrypted := rtpTestCases()[0].encrypted(profile)
 
 	encryptedPkt := &rtp.Packet{
 		Payload: encrypted,
@@ -425,11 +517,12 @@ func BenchmarkDecryptRTP(b *testing.B) {
 		b.Fatal(err)
 	}
 
-	context, err := buildTestContext()
+	context, err := buildTestContext(profile)
 	if err != nil {
 		b.Fatal(err)
 	}
 
+	b.SetBytes(int64(len(encryptedRaw)))
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
@@ -440,59 +533,130 @@ func BenchmarkDecryptRTP(b *testing.B) {
 	}
 }
 
+func BenchmarkDecryptRTP(b *testing.B) {
+	b.Run("CTR", func(b *testing.B) { benchmarkDecryptRTP(b, profileCTR) })
+	b.Run("GCM", func(b *testing.B) { benchmarkDecryptRTP(b, profileGCM) })
+}
+
 func TestRolloverCount2(t *testing.T) {
 	s := &srtpSSRCState{ssrc: defaultSsrc}
 
-	roc, update := s.nextRolloverCount(30123)
+	roc, diff := s.nextRolloverCount(30123)
 	if roc != 0 {
 		t.Errorf("Initial rolloverCounter must be 0")
 	}
-	update()
+	s.updateRolloverCount(30123, diff)
 
-	roc, update = s.nextRolloverCount(62892) // 30123 + (1 << 15) + 1
+	roc, diff = s.nextRolloverCount(62892) // 30123 + (1 << 15) + 1
 	if roc != 0 {
 		t.Errorf("Initial rolloverCounter must be 0")
 	}
-	update()
-	roc, update = s.nextRolloverCount(204)
+	s.updateRolloverCount(62892, diff)
+	roc, diff = s.nextRolloverCount(204)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was not updated after it crossed 0")
 	}
-	update()
-	roc, update = s.nextRolloverCount(64535)
+	s.updateRolloverCount(62892, diff)
+	roc, diff = s.nextRolloverCount(64535)
 	if roc != 0 {
 		t.Errorf("rolloverCounter was not updated when it rolled back, failed to handle out of order")
 	}
-	update()
-	roc, update = s.nextRolloverCount(205)
+	s.updateRolloverCount(64535, diff)
+	roc, diff = s.nextRolloverCount(205)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was improperly updated for non-significant packets")
 	}
-	update()
-	roc, update = s.nextRolloverCount(1)
+	s.updateRolloverCount(205, diff)
+	roc, diff = s.nextRolloverCount(1)
 	if roc != 1 {
 		t.Errorf("rolloverCounter was improperly updated for non-significant packets")
 	}
-	update()
+	s.updateRolloverCount(1, diff)
 
-	roc, update = s.nextRolloverCount(64532)
+	roc, diff = s.nextRolloverCount(64532)
 	if roc != 0 {
 		t.Errorf("rolloverCounter was improperly updated for non-significant packets")
 	}
-	update()
-	roc, update = s.nextRolloverCount(65534)
+	s.updateRolloverCount(64532, diff)
+	roc, diff = s.nextRolloverCount(65534)
 	if roc != 0 {
 		t.Errorf("index was improperly updated for non-significant packets")
 	}
-	update()
-	roc, update = s.nextRolloverCount(64532)
+	s.updateRolloverCount(65534, diff)
+	roc, diff = s.nextRolloverCount(64532)
 	if roc != 0 {
 		t.Errorf("index was improperly updated for non-significant packets")
 	}
-	update()
-	roc, update = s.nextRolloverCount(205)
+	s.updateRolloverCount(65532, diff)
+	roc, diff = s.nextRolloverCount(205)
 	if roc != 1 {
 		t.Errorf("index was not updated after it crossed 0")
 	}
-	update()
+	s.updateRolloverCount(65532, diff)
+}
+
+func TestProtectionProfileAes128CmHmacSha1_32(t *testing.T) {
+	masterKey := []byte{0x0d, 0xcd, 0x21, 0x3e, 0x4c, 0xbc, 0xf2, 0x8f, 0x01, 0x7f, 0x69, 0x94, 0x40, 0x1e, 0x28, 0x89}
+	masterSalt := []byte{0x62, 0x77, 0x60, 0x38, 0xc0, 0x6d, 0xc9, 0x41, 0x9f, 0x6d, 0xd9, 0x43, 0x3e, 0x7c}
+
+	encryptContext, err := CreateContext(masterKey, masterSalt, ProtectionProfileAes128CmHmacSha1_32)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	decryptContext, err := CreateContext(masterKey, masterSalt, ProtectionProfileAes128CmHmacSha1_32)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	pkt := &rtp.Packet{Payload: rtpTestCaseDecrypted(), Header: rtp.Header{SequenceNumber: 5000}}
+	pktRaw, err := pkt.Marshal()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	out, err := encryptContext.EncryptRTP(nil, pktRaw, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	decrypted, err := decryptContext.DecryptRTP(nil, out, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !bytes.Equal(decrypted, pktRaw) {
+		t.Errorf("Decrypted % 02x does not match original % 02x", decrypted, pktRaw)
+	}
+}
+
+func TestRTPDecryptShotenedPacket(t *testing.T) {
+	profiles := map[string]ProtectionProfile{
+		"CTR": profileCTR,
+		"GCM": profileGCM,
+	}
+	for name, profile := range profiles {
+		profile := profile
+		t.Run(name, func(t *testing.T) {
+			for _, testCase := range rtpTestCases() {
+				decryptContext, err := buildTestContext(profile)
+				if err != nil {
+					t.Fatal(err)
+				}
+
+				encryptedPkt := &rtp.Packet{Payload: testCase.encrypted(profile), Header: rtp.Header{SequenceNumber: testCase.sequenceNumber}}
+				encryptedRaw, err := encryptedPkt.Marshal()
+				if err != nil {
+					t.Fatal(err)
+				}
+
+				for i := 1; i < len(encryptedRaw)-1; i++ {
+					packet := encryptedRaw[:i]
+					assert.NotPanics(t, func() {
+						_, _ = decryptContext.DecryptRTP(nil, packet, nil)
+					}, "Panic on length %d/%d", i, len(encryptedRaw))
+				}
+			}
+		})
+	}
 }
diff --git a/stream_srtp_test.go b/stream_srtp_test.go
index 1fbe760..6907e92 100644
--- a/stream_srtp_test.go
+++ b/stream_srtp_test.go
@@ -61,17 +61,26 @@ func TestBufferFactory(t *testing.T) {
 	wg.Wait()
 }
 
-func BenchmarkWrite(b *testing.B) {
+func benchmarkWrite(b *testing.B, profile ProtectionProfile, size int) {
 	conn := newNoopConn()
 
+	keyLen, err := profile.keyLen()
+	if err != nil {
+		b.Fatal(err)
+	}
+	saltLen, err := profile.saltLen()
+	if err != nil {
+		b.Fatal(err)
+	}
+
 	config := &Config{
 		Keys: SessionKeys{
-			LocalMasterKey:   make([]byte, 16),
-			LocalMasterSalt:  make([]byte, 14),
-			RemoteMasterKey:  make([]byte, 16),
-			RemoteMasterSalt: make([]byte, 14),
+			LocalMasterKey:   make([]byte, keyLen),
+			LocalMasterSalt:  make([]byte, saltLen),
+			RemoteMasterKey:  make([]byte, keyLen),
+			RemoteMasterSalt: make([]byte, saltLen),
 		},
-		Profile: ProtectionProfileAes128CmHmacSha1_80,
+		Profile: profile,
 	}
 
 	session, err := NewSessionSRTP(conn, config)
@@ -89,7 +98,7 @@ func BenchmarkWrite(b *testing.B) {
 			Version: 2,
 			SSRC:    322,
 		},
-		Payload: make([]byte, 100),
+		Payload: make([]byte, size),
 	}
 
 	packetRaw, err := packet.Marshal()
@@ -97,6 +106,7 @@ func BenchmarkWrite(b *testing.B) {
 		b.Fatal(err)
 	}
 
+	b.SetBytes(int64(len(packetRaw)))
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
@@ -114,19 +124,43 @@ func BenchmarkWrite(b *testing.B) {
 	}
 }
 
-func BenchmarkWriteRTP(b *testing.B) {
+func BenchmarkWrite(b *testing.B) {
+	b.Run("CTR-100", func(b *testing.B) {
+		benchmarkWrite(b, profileCTR, 100)
+	})
+	b.Run("CTR-1000", func(b *testing.B) {
+		benchmarkWrite(b, profileCTR, 1000)
+	})
+	b.Run("GCM-100", func(b *testing.B) {
+		benchmarkWrite(b, profileGCM, 100)
+	})
+	b.Run("GCM-1000", func(b *testing.B) {
+		benchmarkWrite(b, profileGCM, 1000)
+	})
+}
+
+func benchmarkWriteRTP(b *testing.B, profile ProtectionProfile, size int) {
 	conn := &noopConn{
 		closed: make(chan struct{}),
 	}
 
+	keyLen, err := profile.keyLen()
+	if err != nil {
+		b.Fatal(err)
+	}
+	saltLen, err := profile.saltLen()
+	if err != nil {
+		b.Fatal(err)
+	}
+
 	config := &Config{
 		Keys: SessionKeys{
-			LocalMasterKey:   make([]byte, 16),
-			LocalMasterSalt:  make([]byte, 14),
-			RemoteMasterKey:  make([]byte, 16),
-			RemoteMasterSalt: make([]byte, 14),
+			LocalMasterKey:   make([]byte, keyLen),
+			LocalMasterSalt:  make([]byte, saltLen),
+			RemoteMasterKey:  make([]byte, keyLen),
+			RemoteMasterSalt: make([]byte, saltLen),
 		},
-		Profile: ProtectionProfileAes128CmHmacSha1_80,
+		Profile: profile,
 	}
 
 	session, err := NewSessionSRTP(conn, config)
@@ -144,8 +178,9 @@ func BenchmarkWriteRTP(b *testing.B) {
 		SSRC:    322,
 	}
 
-	payload := make([]byte, 100)
+	payload := make([]byte, size)
 
+	b.SetBytes(int64(header.MarshalSize() + len(payload)))
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
@@ -162,3 +197,18 @@ func BenchmarkWriteRTP(b *testing.B) {
 		b.Fatal(err)
 	}
 }
+
+func BenchmarkWriteRTP(b *testing.B) {
+	b.Run("CTR-100", func(b *testing.B) {
+		benchmarkWriteRTP(b, profileCTR, 100)
+	})
+	b.Run("CTR-1000", func(b *testing.B) {
+		benchmarkWriteRTP(b, profileCTR, 1000)
+	})
+	b.Run("GCM-100", func(b *testing.B) {
+		benchmarkWriteRTP(b, profileGCM, 100)
+	})
+	b.Run("GCM-1000", func(b *testing.B) {
+		benchmarkWriteRTP(b, profileGCM, 1000)
+	})
+}