diff --git a/package.json b/package.json
index b88a9c4..20da1b9 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "@ldclabs/cose-ts",
   "type": "module",
-  "version": "1.3.0",
+  "version": "1.3.1",
   "author": "0xZensh <txr1883@gmail.com>",
   "description": "Implemented Keys, Algorithms (RFC9053), COSE (RFC9052) and CWT (RFC8392) in TypeScript.",
   "license": "MIT",
@@ -40,6 +40,11 @@
       "browser": "./dist/cwt.js",
       "default": "./dist/cwt.js"
     },
+    "./ecdh": {
+      "types": "./dist/ecdh.d.ts",
+      "browser": "./dist/ecdh.js",
+      "default": "./dist/ecdh.js"
+    },
     "./ecdsa": {
       "types": "./dist/ecdsa.d.ts",
       "browser": "./dist/ecdsa.js",
diff --git a/src/key.test.ts b/src/key.test.ts
index 6ab24eb..d62428a 100644
--- a/src/key.test.ts
+++ b/src/key.test.ts
@@ -2,15 +2,15 @@
 // See the file LICENSE for licensing terms.
 
 import { assert, describe, it } from 'vitest'
+import * as iana from './iana'
+import { Key } from './key'
 import {
   bytesToHex,
-  hexToBytes,
-  utf8ToBytes,
   compareBytes,
-  encodeCBOR
+  encodeCBOR,
+  hexToBytes,
+  utf8ToBytes
 } from './utils'
-import * as iana from './iana'
-import { Key } from './key'
 
 describe('Key Examples', () => {
   it('Key', () => {
@@ -42,6 +42,10 @@ describe('Key Examples', () => {
     const expected =
       'a40104024c53796d6d6574726963313238030a2050231f4c4d4d3051fdc2ec0a3851d5b383'
     assert.equal(bytesToHex(key.toBytes()), expected)
+    assert.equal(
+      bytesToHex(key.getSecret()),
+      '231f4c4d4d3051fdc2ec0a3851d5b383'
+    )
 
     const key2 = Key.fromBytes(hexToBytes(expected))
     assert.equal(bytesToHex(key2.toBytes()), expected)
@@ -61,6 +65,10 @@ describe('Key Examples', () => {
     const expected =
       'a40104024c53796d6d65747269633235360304205820403697de87af64611c1d32a05dab0fe1fcb715a86ab435f1ec99192d79569388'
     assert.equal(bytesToHex(key.toBytes()), expected)
+    assert.equal(
+      bytesToHex(key.getSecret()),
+      '403697de87af64611c1d32a05dab0fe1fcb715a86ab435f1ec99192d79569388'
+    )
 
     const key2 = Key.fromBytes(hexToBytes(expected))
     assert.equal(bytesToHex(key2.toBytes()), expected)
@@ -93,6 +101,10 @@ describe('Key Examples', () => {
     const expected =
       'a7010202524173796d6d6574726963454344534132353603262001215820143329cce7868e416927599cf65a34f3ce2ffda55a7eca69ed8919a394d42f0f22582060f7f1a780d8a783bfb7a2dd6b2796e8128dbbcef9d3d168db9529971a36e7b92358206c1382765aec5358f117733d281c1c7bdc39884d04a45a1e6c67c858bc206c19'
     assert.equal(bytesToHex(key.toBytes()), expected)
+    assert.equal(
+      bytesToHex(key.getSecret()),
+      '6c1382765aec5358f117733d281c1c7bdc39884d04a45a1e6c67c858bc206c19'
+    )
 
     const key2 = Key.fromBytes(hexToBytes(expected))
     assert.equal(bytesToHex(key2.toBytes()), expected)
diff --git a/src/key.ts b/src/key.ts
index 729cdde..817acd3 100644
--- a/src/key.ts
+++ b/src/key.ts
@@ -101,4 +101,17 @@ export class Key extends KVMap {
     this.setParam(iana.KeyParameterKid, encodeCBOR(kid))
     return this
   }
+
+  getSecret(): Uint8Array {
+    switch (this.kty) {
+      case iana.KeyTypeOKP:
+        return this.getBytes(iana.OKPKeyParameterD, 'k')
+      case iana.KeyTypeEC2:
+        return this.getBytes(iana.EC2KeyParameterD, 'd')
+      case iana.KeyTypeSymmetric:
+        return this.getBytes(iana.SymmetricKeyParameterK, 'k')
+      default:
+        throw new Error('unsupported key type')
+    }
+  }
 }