diff --git a/package.json b/package.json
index 82e8c83d7..88694670c 100644
--- a/package.json
+++ b/package.json
@@ -141,7 +141,7 @@
     "prettier": "^2.2.0",
     "process": "^0.11.10",
     "react-native-piratechain": "^0.3.2",
-    "react-native-zcash": "^0.3.2",
+    "react-native-zcash": "0.4.0",
     "rimraf": "^3.0.2",
     "stream-browserify": "^2.0.2",
     "stream-http": "^3.2.0",
@@ -155,6 +155,6 @@
   },
   "peerDependencies": {
     "react-native-piratechain": "^0.3.2",
-    "react-native-zcash": "^0.3.2"
+    "react-native-zcash": "^0.4.0"
   }
 }
diff --git a/src/react-native.ts b/src/react-native.ts
index d9fd35497..b5a38bc3b 100644
--- a/src/react-native.ts
+++ b/src/react-native.ts
@@ -7,10 +7,9 @@ import {
   Synchronizer as PirateSynchronizer
 } from 'react-native-piratechain'
 import {
-  AddressTool as ZcashAddressTool,
-  KeyTool as ZcashKeyTool,
   makeSynchronizer as ZcashMakeSynchronizer,
-  Synchronizer as ZcashSynchronizer
+  Synchronizer as ZcashSynchronizer,
+  Tools as ZcashNativeTools
 } from 'react-native-zcash'
 import { bridgifyObject, emit, onMethod } from 'yaob'
 
@@ -79,20 +78,20 @@ const makeZcashSynchronizer = async (
   const out: ZcashSynchronizer = bridgifyObject({
     // @ts-expect-error
     on: onMethod,
-    start: async () => {
-      return await realSynchronizer.start()
+    deriveUnifiedAddress: async () => {
+      return await realSynchronizer.deriveUnifiedAddress()
     },
     getTransactions: async blockRange => {
       return await realSynchronizer.getTransactions(blockRange)
     },
-    rescan: height => {
-      return realSynchronizer.rescan(height)
+    rescan: () => {
+      return realSynchronizer.rescan()
     },
     sendToAddress: async spendInfo => {
       return await realSynchronizer.sendToAddress(spendInfo)
     },
-    getShieldedBalance: async () => {
-      return await realSynchronizer.getShieldedBalance()
+    getBalance: async () => {
+      return await realSynchronizer.getBalance()
     },
     stop: async () => {
       return await realSynchronizer.stop()
@@ -104,8 +103,7 @@ const makeZcashSynchronizer = async (
 export function makePluginIo(): EdgeOtherMethods {
   bridgifyObject(PiratechainKeyTool)
   bridgifyObject(PiratechainAddressTool)
-  bridgifyObject(ZcashKeyTool)
-  bridgifyObject(ZcashAddressTool)
+  bridgifyObject(ZcashNativeTools)
 
   return {
     async fetchText(uri: string, opts: Object) {
@@ -128,8 +126,7 @@ export function makePluginIo(): EdgeOtherMethods {
       }
     }),
     zcash: bridgifyObject({
-      KeyTool: ZcashKeyTool,
-      AddressTool: ZcashAddressTool,
+      Tools: ZcashNativeTools,
       async makeSynchronizer(config: ZcashInitializerConfig) {
         return await makeZcashSynchronizer(config)
       }
diff --git a/src/zcash/ZcashEngine.ts b/src/zcash/ZcashEngine.ts
index f6f2cd546..0579d08c6 100644
--- a/src/zcash/ZcashEngine.ts
+++ b/src/zcash/ZcashEngine.ts
@@ -3,6 +3,7 @@ import {
   EdgeCurrencyEngine,
   EdgeCurrencyEngineOptions,
   EdgeEnginePrivateKeyOptions,
+  EdgeFreshAddress,
   EdgeSpendInfo,
   EdgeTransaction,
   EdgeWalletInfo,
@@ -35,18 +36,21 @@ export class ZcashEngine extends CurrencyEngine<
   pluginId: string
   networkInfo: ZcashNetworkInfo
   otherData!: ZcashWalletOtherData
-  synchronizer!: ZcashSynchronizer
   synchronizerStatus!: ZcashSynchronizerStatus
   availableZatoshi!: string
   initialNumBlocksToDownload!: number
   initializer!: ZcashInitializerConfig
-  alias!: string
   progressRatio!: number
   queryMutex: boolean
   makeSynchronizer: (
     config: ZcashInitializerConfig
   ) => Promise<ZcashSynchronizer>
 
+  // Synchronizer management
+  started: boolean
+  stopSyncing?: (value: number | PromiseLike<number>) => void
+  synchronizer?: ZcashSynchronizer
+
   constructor(
     env: PluginEnvironment<ZcashNetworkInfo>,
     tools: ZcashTools,
@@ -60,6 +64,8 @@ export class ZcashEngine extends CurrencyEngine<
     this.networkInfo = networkInfo
     this.makeSynchronizer = makeSynchronizer
     this.queryMutex = false
+
+    this.started = false
   }
 
   setOtherData(raw: any): void {
@@ -67,7 +73,7 @@ export class ZcashEngine extends CurrencyEngine<
   }
 
   initData(): void {
-    const { birthdayHeight, alias } = this.initializer
+    const { birthdayHeight } = this.initializer
 
     // walletLocalData
     if (this.otherData.blockRange.first === 0) {
@@ -78,7 +84,6 @@ export class ZcashEngine extends CurrencyEngine<
     }
 
     // Engine variables
-    this.alias = alias
     this.initialNumBlocksToDownload = -1
     this.synchronizerStatus = 'DISCONNECTED'
     this.availableZatoshi = '0'
@@ -86,6 +91,7 @@ export class ZcashEngine extends CurrencyEngine<
   }
 
   initSubscriptions(): void {
+    if (this.synchronizer == null) return
     this.synchronizer.on('update', async payload => {
       const { lastDownloadedHeight, scanProgress, networkBlockHeight } = payload
       this.onUpdateBlockHeight(networkBlockHeight)
@@ -175,10 +181,8 @@ export class ZcashEngine extends CurrencyEngine<
   }
 
   async startEngine(): Promise<void> {
-    this.initData()
-    this.synchronizer = await this.makeSynchronizer(this.initializer)
-    await this.synchronizer.start()
-    this.initSubscriptions()
+    this.engineOn = true
+    this.started = true
     await super.startEngine()
   }
 
@@ -188,9 +192,9 @@ export class ZcashEngine extends CurrencyEngine<
   }
 
   async queryBalance(): Promise<void> {
-    if (!this.isSynced()) return
+    if (!this.isSynced() || this.synchronizer == null) return
     try {
-      const balances = await this.synchronizer.getShieldedBalance()
+      const balances = await this.synchronizer.getBalance()
       if (balances.totalZatoshi === '-1') return
       this.availableZatoshi = balances.availableZatoshi
       this.updateBalance(this.currencyInfo.currencyCode, balances.totalZatoshi)
@@ -201,6 +205,7 @@ export class ZcashEngine extends CurrencyEngine<
   }
 
   async queryTransactions(): Promise<void> {
+    if (this.synchronizer == null) return
     try {
       let first = this.otherData.blockRange.first
       let last = this.otherData.blockRange.last
@@ -270,8 +275,37 @@ export class ZcashEngine extends CurrencyEngine<
     this.addTransaction(this.currencyInfo.currencyCode, edgeTransaction)
   }
 
+  async syncNetwork(opts: EdgeEnginePrivateKeyOptions): Promise<number> {
+    if (!this.started) return 1000
+
+    const zcashPrivateKeys = asZcashPrivateKeys(this.currencyInfo.pluginId)(
+      opts?.privateKeys
+    )
+
+    const { rpcNode } = this.networkInfo
+    this.initializer = {
+      mnemonicSeed: zcashPrivateKeys.mnemonic,
+      birthdayHeight: zcashPrivateKeys.birthdayHeight,
+      alias: this.walletInfo.keys.publicKey.slice(0, 99),
+      ...rpcNode
+    }
+
+    this.synchronizer = await this.makeSynchronizer(this.initializer)
+    this.initData()
+    this.initSubscriptions()
+
+    return await new Promise(resolve => {
+      this.stopSyncing = resolve
+    })
+  }
+
   async killEngine(): Promise<void> {
-    await this.synchronizer.stop()
+    this.started = false
+    if (this.stopSyncing != null) {
+      await this.stopSyncing(1000)
+      this.stopSyncing = undefined
+    }
+    await this.synchronizer?.stop()
     await super.killEngine()
   }
 
@@ -285,8 +319,10 @@ export class ZcashEngine extends CurrencyEngine<
     await this.clearBlockchainCache()
     await this.startEngine()
     this.synchronizer
-      .rescan(this.walletInfo.keys.birthdayHeight)
+      ?.rescan()
       .catch((e: any) => this.warn('resyncBlockchain failed: ', e))
+    this.initData()
+    this.synchronizerStatus = 'SYNCING'
   }
 
   async getMaxSpendable(): Promise<string> {
@@ -364,6 +400,7 @@ export class ZcashEngine extends CurrencyEngine<
     edgeTransaction: EdgeTransaction,
     opts?: EdgeEnginePrivateKeyOptions
   ): Promise<EdgeTransaction> {
+    if (this.synchronizer == null) throw new Error('Synchronizer undefined')
     const zcashPrivateKeys = asZcashPrivateKeys(this.pluginId)(
       opts?.privateKeys
     )
@@ -382,7 +419,7 @@ export class ZcashEngine extends CurrencyEngine<
       toAddress: spendTarget.publicAddress,
       memo: spendTarget.memo ?? spendTarget.uniqueIdentifier ?? '',
       fromAccountIndex: 0,
-      spendingKey: zcashPrivateKeys.spendKey
+      mnemonicSeed: zcashPrivateKeys.mnemonic
     }
 
     try {
@@ -398,20 +435,15 @@ export class ZcashEngine extends CurrencyEngine<
     return edgeTransaction
   }
 
-  async loadEngine(): Promise<void> {
-    const { walletInfo } = this
-    await super.loadEngine()
-    this.engineOn = true
-
-    const { rpcNode } = this.networkInfo
-    this.initializer = {
-      fullViewingKey: walletInfo.keys.unifiedViewingKeys,
-      birthdayHeight: walletInfo.keys.birthdayHeight,
-      alias: walletInfo.keys.publicKey,
-      ...rpcNode
+  async getFreshAddress(): Promise<EdgeFreshAddress> {
+    if (this.synchronizer == null) throw new Error('Synchronizer undefined')
+    const unifiedAddress = await this.synchronizer.deriveUnifiedAddress()
+    return {
+      publicAddress: unifiedAddress
     }
   }
 }
+
 export async function makeCurrencyEngine(
   env: PluginEnvironment<ZcashNetworkInfo>,
   tools: ZcashTools,
diff --git a/src/zcash/ZcashTools.ts b/src/zcash/ZcashTools.ts
index da557f01d..589753eae 100644
--- a/src/zcash/ZcashTools.ts
+++ b/src/zcash/ZcashTools.ts
@@ -1,5 +1,5 @@
 import { div } from 'biggystring'
-import { entropyToMnemonic, mnemonicToSeed, validateMnemonic } from 'bip39'
+import { entropyToMnemonic, validateMnemonic } from 'bip39'
 import { Buffer } from 'buffer'
 import {
   EdgeCurrencyInfo,
@@ -12,10 +12,7 @@ import {
   EdgeWalletInfo,
   JsonObject
 } from 'edge-core-js/types'
-import {
-  AddressTool as AddressToolType,
-  KeyTool as KeyToolType
-} from 'react-native-zcash'
+import { Tools as ToolsType } from 'react-native-zcash'
 
 import { PluginEnvironment } from '../common/innerPlugin'
 import { asIntegerString } from '../common/types'
@@ -34,9 +31,7 @@ export class ZcashTools implements EdgeCurrencyTools {
   currencyInfo: EdgeCurrencyInfo
   io: EdgeIo
   networkInfo: ZcashNetworkInfo
-
-  KeyTool: typeof KeyToolType
-  AddressTool: typeof AddressToolType
+  nativeTools: typeof ToolsType
 
   constructor(env: PluginEnvironment<ZcashNetworkInfo>) {
     const { builtinTokens, currencyInfo, io, networkInfo } = env
@@ -51,8 +46,7 @@ export class ZcashTools implements EdgeCurrencyTools {
     }
     const { Tools } = RNAccountbased.zcash
 
-    this.KeyTool = KeyTool
-    this.AddressTool = AddressTool
+    this.nativeTools = Tools
   }
 
   async getDisplayPrivateKey(
@@ -65,12 +59,12 @@ export class ZcashTools implements EdgeCurrencyTools {
 
   async getDisplayPublicKey(publicWalletInfo: EdgeWalletInfo): Promise<string> {
     const { keys } = asSafeZcashWalletInfo(publicWalletInfo)
-    return keys.unifiedViewingKeys?.extfvk
+    return keys.publicKey
   }
 
   async getNewWalletBirthdayBlockheight(): Promise<number> {
     try {
-      return await this.KeyTool.getBirthdayHeight(
+      return await this.nativeTools.getBirthdayHeight(
         this.networkInfo.rpcNode.defaultHost,
         this.networkInfo.rpcNode.defaultPort
       )
@@ -80,10 +74,7 @@ export class ZcashTools implements EdgeCurrencyTools {
   }
 
   async isValidAddress(address: string): Promise<boolean> {
-    return (
-      (await this.AddressTool.isValidShieldedAddress(address)) ||
-      (await this.AddressTool.isValidTransparentAddress(address))
-    )
+    return await this.nativeTools.isValidAddress(address)
   }
 
   // will actually use MNEMONIC version of private key
@@ -95,13 +86,6 @@ export class ZcashTools implements EdgeCurrencyTools {
     const isValid = validateMnemonic(userInput)
     if (!isValid)
       throw new Error(`Invalid ${this.currencyInfo.currencyCode} mnemonic`)
-    const hexBuffer = await mnemonicToSeed(userInput)
-    const hex = hexBuffer.toString('hex')
-    const spendKey = await this.KeyTool.deriveSpendingKey(
-      hex,
-      this.networkInfo.rpcNode.networkName
-    )
-    if (typeof spendKey !== 'string') throw new Error('Invalid spendKey type')
 
     // Get current network height for the birthday height
     const currentNetworkHeight = await this.getNewWalletBirthdayBlockheight()
@@ -122,7 +106,6 @@ export class ZcashTools implements EdgeCurrencyTools {
 
     return {
       [`${pluginId}Mnemonic`]: userInput,
-      [`${pluginId}SpendKey`]: spendKey,
       [`${pluginId}BirthdayHeight`]: height
     }
   }
@@ -157,21 +140,14 @@ export class ZcashTools implements EdgeCurrencyTools {
     if (typeof mnemonic !== 'string') {
       throw new Error('InvalidMnemonic')
     }
-    const hexBuffer = await mnemonicToSeed(mnemonic)
-    const hex = hexBuffer.toString('hex')
-    const unifiedViewingKeys: UnifiedViewingKey =
-      await this.KeyTool.deriveViewingKey(
-        hex,
+    const unifiedViewingKey: UnifiedViewingKey =
+      await this.nativeTools.deriveViewingKey(
+        mnemonic,
         this.networkInfo.rpcNode.networkName
       )
-    const shieldedAddress = await this.AddressTool.deriveShieldedAddress(
-      unifiedViewingKeys.extfvk,
-      this.networkInfo.rpcNode.networkName
-    )
     return {
       birthdayHeight: zcashPrivateKeys.birthdayHeight,
-      publicKey: shieldedAddress,
-      unifiedViewingKeys
+      publicKey: unifiedViewingKey
     }
   }
 
diff --git a/src/zcash/zcashInfo.ts b/src/zcash/zcashInfo.ts
index 1f2a603ad..45039aca4 100644
--- a/src/zcash/zcashInfo.ts
+++ b/src/zcash/zcashInfo.ts
@@ -40,6 +40,7 @@ export const currencyInfo: EdgeCurrencyInfo = {
 
   metaTokens: [], // Deprecated
 
+  unsafeSyncNetwork: true,
   unsafeBroadcastTx: true
 }
 
diff --git a/src/zcash/zcashTypes.ts b/src/zcash/zcashTypes.ts
index 9b645cf1f..26b4a353a 100644
--- a/src/zcash/zcashTypes.ts
+++ b/src/zcash/zcashTypes.ts
@@ -28,7 +28,7 @@ export interface ZcashSpendInfo {
   toAddress: string
   memo: string
   fromAccountIndex: number
-  spendingKey: string
+  mnemonicSeed: string
 }
 
 export interface ZcashTransaction {
@@ -59,7 +59,7 @@ export interface ZcashInitializerConfig {
   networkName: ZcashNetworkName
   defaultHost: string
   defaultPort: number
-  fullViewingKey: UnifiedViewingKey
+  mnemonicSeed: string
   alias: string
   birthdayHeight: number
 }
@@ -67,10 +67,7 @@ export interface ZcashInitializerConfig {
 export type ZcashSynchronizerStatus =
   | 'STOPPED'
   | 'DISCONNECTED'
-  | 'DOWNLOADING'
-  | 'VALIDATING'
-  | 'SCANNING'
-  | 'ENHANCING'
+  | 'SYNCING'
   | 'SYNCED'
 
 export interface ZcashStatusEvent {
@@ -113,10 +110,11 @@ export interface ZcashSynchronizer {
   }>
   start: () => Promise<void>
   stop: () => Promise<void>
+  deriveUnifiedAddress: () => Promise<string>
   getTransactions: (arg: ZcashBlockRange) => Promise<ZcashTransaction[]>
-  rescan: (arg: number) => Promise<string>
+  rescan: () => Promise<string>
   sendToAddress: (arg: ZcashSpendInfo) => Promise<ZcashPendingTransaction>
-  getShieldedBalance: () => Promise<ZcashWalletBalance>
+  getBalance: () => Promise<ZcashWalletBalance>
 }
 
 export type ZcashMakeSynchronizer = () => (
@@ -125,11 +123,7 @@ export type ZcashMakeSynchronizer = () => (
 
 export const asZecPublicKey = asObject({
   birthdayHeight: asNumber,
-  publicKey: asString,
-  unifiedViewingKeys: asObject({
-    extfvk: asString,
-    extpub: asString
-  })
+  publicKey: asString
 })
 
 export type SafeZcashWalletInfo = ReturnType<typeof asSafeZcashWalletInfo>
@@ -137,7 +131,6 @@ export const asSafeZcashWalletInfo = asWalletInfo(asZecPublicKey)
 
 export interface ZcashPrivateKeys {
   mnemonic: string
-  spendKey: string
   birthdayHeight: number
 }
 export const asZcashPrivateKeys = (
@@ -145,7 +138,6 @@ export const asZcashPrivateKeys = (
 ): Cleaner<ZcashPrivateKeys> => {
   const asKeys = asObject({
     [`${pluginId}Mnemonic`]: asString,
-    [`${pluginId}SpendKey`]: asString,
     [`${pluginId}BirthdayHeight`]: asNumber
   })
 
@@ -154,14 +146,12 @@ export const asZcashPrivateKeys = (
       const clean = asKeys(raw)
       return {
         mnemonic: clean[`${pluginId}Mnemonic`] as string,
-        spendKey: clean[`${pluginId}SpendKey`] as string,
         birthdayHeight: clean[`${pluginId}BirthdayHeight`] as number
       }
     },
     clean => {
       return {
         [`${pluginId}Mnemonic`]: clean.mnemonic,
-        [`${pluginId}SpendKey`]: clean.spendKey,
         [`${pluginId}BirthdayHeight`]: clean.birthdayHeight
       }
     }
diff --git a/yarn.lock b/yarn.lock
index cef35f7d7..7ce9960e7 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -6681,10 +6681,10 @@ react-native-piratechain@^0.3.2:
   dependencies:
     rfc4648 "^1.3.0"
 
-react-native-zcash@^0.3.2:
-  version "0.3.2"
-  resolved "https://registry.yarnpkg.com/react-native-zcash/-/react-native-zcash-0.3.2.tgz#f2b77630ab104771e844b07e43269a0fb3d33a63"
-  integrity sha512-6qukZUUDzEeuVL7h9jq1wek2UDo2KT3QvDuw7FISeoXUug1LAAgPvLE36v51smcdNQamLMBqJWAZM1tS3B5xTw==
+react-native-zcash@0.4.0:
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/react-native-zcash/-/react-native-zcash-0.4.0.tgz#cd6cc045673a5bf843a2c5e342b66ee243239555"
+  integrity sha512-xL87jBLiCqqpKJ4Mir/cC4M+poJYvFu6z9Mad0rGO+zOxfBkVuvunm4kYBtx96bqVHDH3jX9CukE888MBZzFAQ==
   dependencies:
     rfc4648 "^1.3.0"