diff --git a/src/dtls13.c b/src/dtls13.c
index d6e1d3d239..f091ed62ff 100644
--- a/src/dtls13.c
+++ b/src/dtls13.c
@@ -341,9 +341,17 @@ static void Dtls13MsgWasProcessed(WOLFSSL* ssl, enum HandShakeType hs)
     if (ssl->options.dtlsStateful)
         ssl->keys.dtls_expected_peer_handshake_number++;
 
-    /* we need to send ACKs on the last message of a flight that needs explicit
-       acknowledgment */
-    ssl->dtls13Rtx.sendAcks = Dtls13RtxMsgNeedsAck(ssl, hs);
+#ifdef WOLFSSL_RW_THREADED
+    if (wc_LockMutex(&ssl->dtls13Rtx.mutex) == 0)
+#endif
+    {
+        /* we need to send ACKs on the last message of a flight that needs
+         * explicit acknowledgment */
+        ssl->dtls13Rtx.sendAcks = Dtls13RtxMsgNeedsAck(ssl, hs);
+    #ifdef WOLFSSL_RW_THREADED
+        wc_UnLockMutex(&ssl->dtls13Rtx.mutex);
+    #endif
+    }
 }
 
 int Dtls13ProcessBufferedMessages(WOLFSSL* ssl)
@@ -654,8 +662,17 @@ static void Dtls13RtxRecordUnlink(WOLFSSL* ssl, Dtls13RtxRecord** prevNext,
     Dtls13RtxRecord* r)
 {
     /* if r was at the tail of the list, update the tail pointer */
-    if (r->next == NULL)
-        ssl->dtls13Rtx.rtxRecordTailPtr = prevNext;
+    if (r->next == NULL) {
+    #ifdef WOLFSSL_RW_THREADED
+        if (wc_LockMutex(&ssl->dtls13Rtx.mutex) == 0)
+    #endif
+        {
+            ssl->dtls13Rtx.rtxRecordTailPtr = prevNext;
+        #ifdef WOLFSSL_RW_THREADED
+            wc_UnLockMutex(&ssl->dtls13Rtx.mutex);
+        #endif
+        }
+    }
 
     /* unlink */
     *prevNext = r->next;
@@ -712,12 +729,20 @@ static int Dtls13RtxAddAck(WOLFSSL* ssl, w64wrapper epoch, w64wrapper seq)
 
     WOLFSSL_ENTER("Dtls13RtxAddAck");
 
-    rn = Dtls13NewRecordNumber(epoch, seq, ssl->heap);
-    if (rn == NULL)
-        return MEMORY_E;
+#ifdef WOLFSSL_RW_THREADED
+    if (wc_LockMutex(&ssl->dtls13Rtx.mutex) == 0)
+#endif
+    {
+        rn = Dtls13NewRecordNumber(epoch, seq, ssl->heap);
+        if (rn == NULL)
+            return MEMORY_E;
 
-    rn->next = ssl->dtls13Rtx.seenRecords;
-    ssl->dtls13Rtx.seenRecords = rn;
+        rn->next = ssl->dtls13Rtx.seenRecords;
+        ssl->dtls13Rtx.seenRecords = rn;
+    #ifdef WOLFSSL_RW_THREADED
+        wc_UnLockMutex(&ssl->dtls13Rtx.mutex);
+    #endif
+    }
 
     return 0;
 }
@@ -730,15 +755,23 @@ static void Dtls13RtxFlushAcks(WOLFSSL* ssl)
 
     WOLFSSL_ENTER("Dtls13RtxFlushAcks");
 
-    list = ssl->dtls13Rtx.seenRecords;
+#ifdef WOLFSSL_RW_THREADED
+    if (wc_LockMutex(&ssl->dtls13Rtx.mutex) == 0)
+#endif
+    {
+        list = ssl->dtls13Rtx.seenRecords;
 
-    while (list != NULL) {
-        rn = list;
-        list = rn->next;
-        XFREE(rn, ssl->heap, DYNAMIC_TYPE_DTLS_MSG);
-    }
+        while (list != NULL) {
+            rn = list;
+            list = rn->next;
+            XFREE(rn, ssl->heap, DYNAMIC_TYPE_DTLS_MSG);
+        }
 
-    ssl->dtls13Rtx.seenRecords = NULL;
+        ssl->dtls13Rtx.seenRecords = NULL;
+    #ifdef WOLFSSL_RW_THREADED
+        wc_UnLockMutex(&ssl->dtls13Rtx.mutex);
+    #endif
+    }
 }
 
 static int Dtls13DetectDisruption(WOLFSSL* ssl, word32 fragOffset)
@@ -2519,13 +2552,25 @@ static void Dtls13RtxRemoveRecord(WOLFSSL* ssl, w64wrapper epoch,
 int Dtls13DoScheduledWork(WOLFSSL* ssl)
 {
     int ret;
+    int sendAcks;
 
     WOLFSSL_ENTER("Dtls13DoScheduledWork");
 
     ssl->dtls13SendingAckOrRtx = 1;
 
-    if (ssl->dtls13Rtx.sendAcks) {
+#ifdef WOLFSSL_RW_THREADED
+    ret = wc_LockMutex(&ssl->dtls13Rtx.mutex);
+    if (ret < 0)
+        return ret;
+#endif
+    sendAcks = ssl->dtls13Rtx.sendAcks;
+    if (sendAcks) {
         ssl->dtls13Rtx.sendAcks = 0;
+    }
+#ifdef WOLFSSL_RW_THREADED
+    ret = wc_UnLockMutex(&ssl->dtls13Rtx.mutex);
+#endif
+    if (sendAcks) {
         ret = SendDtls13Ack(ssl);
         if (ret != 0)
             return ret;
@@ -2601,13 +2646,28 @@ static int Dtls13RtxHasKeyUpdateBuffered(WOLFSSL* ssl)
     return 0;
 }
 
+int DoDtls13KeyUpdateAck(WOLFSSL* ssl)
+{
+    int ret = 0;
+
+    if (!Dtls13RtxHasKeyUpdateBuffered(ssl)) {
+        /* we removed the KeyUpdate message because it was ACKed */
+        ssl->dtls13WaitKeyUpdateAck = 0;
+        ret = Dtls13KeyUpdateAckReceived(ssl);
+    }
+
+    return ret;
+}
+
 int DoDtls13Ack(WOLFSSL* ssl, const byte* input, word32 inputSize,
     word32* processedSize)
 {
     const byte* ackMessage;
     w64wrapper epoch, seq;
     word16 length;
+#ifndef WOLFSSL_RW_THREADED
     int ret;
+#endif
     int i;
 
     if (inputSize < OPAQUE16_LEN)
@@ -2639,15 +2699,13 @@ int DoDtls13Ack(WOLFSSL* ssl, const byte* input, word32 inputSize,
         ssl->options.serverState = SERVER_FINISHED_ACKED;
     }
 
+#ifndef WOLFSSL_RW_THREADED
     if (ssl->dtls13WaitKeyUpdateAck) {
-        if (!Dtls13RtxHasKeyUpdateBuffered(ssl)) {
-            /* we removed the KeyUpdate message because it was ACKed */
-            ssl->dtls13WaitKeyUpdateAck = 0;
-            ret = Dtls13KeyUpdateAckReceived(ssl);
-            if (ret != 0)
-                return ret;
-        }
+        ret = DoDtls13KeyUpdateAck(ssl);
+        if (ret != 0)
+            return ret;
     }
+#endif
 
     *processedSize = length + OPAQUE16_LEN;
 
@@ -2698,9 +2756,17 @@ int SendDtls13Ack(WOLFSSL* ssl)
     if (ret != 0)
         return ret;
 
-    ret = Dtls13WriteAckMessage(ssl, ssl->dtls13Rtx.seenRecords, &length);
-    if (ret != 0)
+#ifdef WOLFSSL_RW_THREADED
+    ret = wc_LockMutex(&ssl->dtls13Rtx.mutex);
+    if (ret < 0)
         return ret;
+#endif
+    ret = Dtls13WriteAckMessage(ssl, ssl->dtls13Rtx.seenRecords, &length);
+#ifdef WOLFSSL_RW_THREADED
+    wc_UnLockMutex(&ssl->dtls13Rtx.mutex);
+#endif
+        if (ret != 0)
+            return ret;
 
     output = GetOutputBuffer(ssl);
 
diff --git a/src/internal.c b/src/internal.c
index bf9e7fde53..38a79997a9 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -2885,95 +2885,73 @@ void InitCiphers(WOLFSSL* ssl)
 
 }
 
-
-/* Free ciphers */
-void FreeCiphers(WOLFSSL* ssl)
+static void FreeCiphersSide(Ciphers *cipher, void* heap)
 {
-    (void)ssl;
 #ifdef BUILD_ARC4
-    wc_Arc4Free(ssl->encrypt.arc4);
-    wc_Arc4Free(ssl->decrypt.arc4);
-    XFREE(ssl->encrypt.arc4, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.arc4, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.arc4 = NULL;
-    ssl->decrypt.arc4 = NULL;
+    wc_Arc4Free(cipher->arc4);
+    XFREE(cipher->arc4, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->arc4 = NULL;
 #endif
 #ifdef BUILD_DES3
-    wc_Des3Free(ssl->encrypt.des3);
-    wc_Des3Free(ssl->decrypt.des3);
-    XFREE(ssl->encrypt.des3, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.des3, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.des3 = NULL;
-    ssl->decrypt.des3 = NULL;
+    wc_Des3Free(cipher->des3);
+    XFREE(cipher->des3, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->des3 = NULL;
 #endif
 #if defined(BUILD_AES) || defined(BUILD_AESGCM) || defined(HAVE_ARIA)
-    /* See: InitKeys() in keys.c on addition of BUILD_AESGCM check (enc->aes, dec->aes) */
-    wc_AesFree(ssl->encrypt.aes);
-    wc_AesFree(ssl->decrypt.aes);
-    XFREE(ssl->encrypt.aes, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.aes, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.aes = NULL;
-    ssl->decrypt.aes = NULL;
+    /* See: InitKeys() in keys.c on addition of BUILD_AESGCM check (enc->aes,
+     * dec->aes) */
+    wc_AesFree(cipher->aes);
+    XFREE(cipher->aes, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->aes = NULL;
 #endif
 #if defined(WOLFSSL_SM4_GCM) || defined(WOLFSSL_SM4_CCM)
-    wc_Sm4Free(ssl->encrypt.sm4);
-    wc_Sm4Free(ssl->decrypt.sm4);
-    XFREE(ssl->encrypt.sm4, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.sm4, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.sm4 = NULL;
-    ssl->decrypt.sm4 = NULL;
+    wc_Sm4Free(cipher->sm4);
+    XFREE(cipher->sm4, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->sm4 = NULL;
 #endif
 #if (defined(BUILD_AESGCM) || defined(BUILD_AESCCM) || defined(HAVE_ARIA)) && \
     !defined(WOLFSSL_NO_TLS12)
-    XFREE(ssl->encrypt.additional, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.additional, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.additional = NULL;
-    ssl->decrypt.additional = NULL;
+    XFREE(cipher->additional, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->additional = NULL;
 #endif
 #ifdef CIPHER_NONCE
-    XFREE(ssl->encrypt.nonce, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.nonce, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.nonce = NULL;
-    ssl->decrypt.nonce = NULL;
+    XFREE(cipher->nonce, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->nonce = NULL;
 #endif
 #ifdef HAVE_ARIA
-    wc_AriaFreeCrypt(ssl->encrypt.aria);
-    wc_AriaFreeCrypt(ssl->decrypt.aria);
-    XFREE(ssl->encrypt.aria, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.aria, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.aria = NULL;
-    ssl->decrypt.aria = NULL;
+    wc_AriaFreeCrypt(cipher->aria);
+    XFREE(cipher->aria, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->aria = NULL;
 #endif
 #ifdef HAVE_CAMELLIA
-    XFREE(ssl->encrypt.cam, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.cam, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.cam = NULL;
-    ssl->decrypt.cam = NULL;
+    XFREE(cipher->cam, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->cam = NULL;
 #endif
 #ifdef HAVE_CHACHA
-    if (ssl->encrypt.chacha)
-        ForceZero(ssl->encrypt.chacha, sizeof(ChaCha));
-    if (ssl->decrypt.chacha)
-        ForceZero(ssl->decrypt.chacha, sizeof(ChaCha));
-    XFREE(ssl->encrypt.chacha, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.chacha, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.chacha = NULL;
-    ssl->decrypt.chacha = NULL;
+    if (cipher->chacha)
+        ForceZero(cipher->chacha, sizeof(ChaCha));
+    XFREE(cipher->chacha, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->chacha = NULL;
 #endif
+#if defined(WOLFSSL_TLS13) && defined(HAVE_NULL_CIPHER)
+    wc_HmacFree(cipher->hmac);
+    XFREE(cipher->hmac, heap, DYNAMIC_TYPE_CIPHER);
+    cipher->hmac = NULL;
+#endif
+}
+
+/* Free ciphers */
+void FreeCiphers(WOLFSSL* ssl)
+{
+    FreeCiphersSide(&ssl->encrypt, ssl->heap);
+    FreeCiphersSide(&ssl->decrypt, ssl->heap);
+
 #if defined(HAVE_POLY1305) && defined(HAVE_ONE_TIME_AUTH)
     if (ssl->auth.poly1305)
         ForceZero(ssl->auth.poly1305, sizeof(Poly1305));
     XFREE(ssl->auth.poly1305, ssl->heap, DYNAMIC_TYPE_CIPHER);
     ssl->auth.poly1305 = NULL;
 #endif
-#if defined(WOLFSSL_TLS13) && defined(HAVE_NULL_CIPHER)
-    wc_HmacFree(ssl->encrypt.hmac);
-    wc_HmacFree(ssl->decrypt.hmac);
-    XFREE(ssl->encrypt.hmac, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    XFREE(ssl->decrypt.hmac, ssl->heap, DYNAMIC_TYPE_CIPHER);
-    ssl->encrypt.hmac = NULL;
-    ssl->decrypt.hmac = NULL;
-#endif
 
 #ifdef WOLFSSL_DTLS13
 #ifdef BUILD_AES
@@ -2993,7 +2971,6 @@ void FreeCiphers(WOLFSSL* ssl)
 #endif /* WOLFSSL_DTLS13 */
 }
 
-
 void InitCipherSpecs(CipherSpecs* cs)
 {
     XMEMSET(cs, 0, sizeof(CipherSpecs));
@@ -7392,6 +7369,15 @@ int InitSSL(WOLFSSL* ssl, WOLFSSL_CTX* ctx, int writeDup)
     ssl->buffers.outputBuffer.buffer = ssl->buffers.outputBuffer.staticBuffer;
     ssl->buffers.outputBuffer.bufferSize  = STATIC_BUFFER_LEN;
 
+#ifdef WOLFSSL_THREADED_CRYPT
+    {
+        int i;
+        for (i = 0; i < WOLFSSL_THREADED_CRYPT_CNT; i++) {
+            ssl->buffers.encrypt[i].avail = 1;
+        }
+    }
+#endif
+
 #ifdef KEEP_PEER_CERT
     InitX509(&ssl->peerCert, 0, ssl->heap);
 #endif
@@ -7729,6 +7715,13 @@ int InitSSL(WOLFSSL* ssl, WOLFSSL_CTX* ctx, int writeDup)
     ssl->dtls13DecryptEpoch = &ssl->dtls13Epochs[0];
     ssl->options.dtls13SendMoreAcks = WOLFSSL_DTLS13_SEND_MOREACK_DEFAULT;
     ssl->dtls13Rtx.rtxRecordTailPtr = &ssl->dtls13Rtx.rtxRecords;
+
+#ifdef WOLFSSL_RW_THREADED
+    ret = wc_InitMutex(&ssl->dtls13Rtx.mutex);
+    if (ret < 0) {
+        return ret;
+    }
+#endif
 #endif /* WOLFSSL_DTLS13 */
 
 #ifdef WOLFSSL_QUIC
@@ -8259,6 +8252,25 @@ void SSL_ResourceFree(WOLFSSL* ssl)
         ShrinkInputBuffer(ssl, FORCED_FREE);
     if (ssl->buffers.outputBuffer.dynamicFlag)
         ShrinkOutputBuffer(ssl);
+#ifdef WOLFSSL_THREADED_CRYPT
+    {
+        int i;
+        for (i = 0; i < WOLFSSL_THREADED_CRYPT_CNT; i++) {
+            bufferStatic* buff = &ssl->buffers.encrypt[i].buffer;
+
+            ssl->buffers.encrypt[i].stop = 1;
+            FreeCiphersSide(&ssl->buffers.encrypt[i].encrypt, ssl->heap);
+            if (buff->dynamicFlag) {
+                XFREE(buff->buffer - buff->offset, ssl->heap,
+                    DYNAMIC_TYPE_OUT_BUFFER);
+                buff->buffer      = buff->staticBuffer;
+                buff->bufferSize  = STATIC_BUFFER_LEN;
+                buff->offset      = 0;
+                buff->dynamicFlag = 0;
+            }
+        }
+    }
+#endif
 #if defined(WOLFSSL_SEND_HRR_COOKIE) && !defined(NO_WOLFSSL_SERVER)
     if (ssl->buffers.tls13CookieSecret.buffer != NULL) {
         ForceZero(ssl->buffers.tls13CookieSecret.buffer,
@@ -8511,6 +8523,10 @@ void SSL_ResourceFree(WOLFSSL* ssl)
 #endif
 #ifdef WOLFSSL_DTLS13
     Dtls13FreeFsmResources(ssl);
+
+#ifdef WOLFSSL_RW_THREADED
+    wc_FreeMutex(&ssl->dtls13Rtx.mutex);
+#endif
 #endif /* WOLFSSL_DTLS13 */
 #ifdef WOLFSSL_QUIC
     wolfSSL_quic_free(ssl);
@@ -10770,6 +10786,69 @@ int SendBuffered(WOLFSSL* ssl)
     return 0;
 }
 
+#ifdef WOLFSSL_THREADED_CRYPT
+static WC_INLINE int GrowAnOutputBuffer(WOLFSSL* ssl,
+    bufferStatic* outputBuffer, int size)
+{
+    byte* tmp;
+#if WOLFSSL_GENERAL_ALIGNMENT > 0
+    byte  hdrSz = ssl->options.dtls ? DTLS_RECORD_HEADER_SZ :
+                                      RECORD_HEADER_SZ;
+    byte align = WOLFSSL_GENERAL_ALIGNMENT;
+#else
+    const byte align = WOLFSSL_GENERAL_ALIGNMENT;
+#endif
+
+#if WOLFSSL_GENERAL_ALIGNMENT > 0
+    /* the encrypted data will be offset from the front of the buffer by
+       the header, if the user wants encrypted alignment they need
+       to define their alignment requirement */
+
+    while (align < hdrSz)
+        align *= 2;
+#endif
+
+    tmp = (byte*)XMALLOC(size + outputBuffer->length + align,
+                             ssl->heap, DYNAMIC_TYPE_OUT_BUFFER);
+    WOLFSSL_MSG("growing output buffer");
+
+    if (tmp == NULL)
+        return MEMORY_E;
+
+#if WOLFSSL_GENERAL_ALIGNMENT > 0
+    if (align)
+        tmp += align - hdrSz;
+#endif
+
+#ifdef WOLFSSL_STATIC_MEMORY
+    /* can be from IO memory pool which does not need copy if same buffer */
+    if (outputBuffer->length && tmp == outputBuffer->buffer) {
+        outputBuffer->bufferSize = size + outputBuffer->length;
+        return 0;
+    }
+#endif
+
+    if (outputBuffer->length)
+        XMEMCPY(tmp, outputBuffer->buffer, outputBuffer->length);
+
+    if (outputBuffer->dynamicFlag) {
+        XFREE(outputBuffer->buffer - outputBuffer->offset, ssl->heap,
+              DYNAMIC_TYPE_OUT_BUFFER);
+    }
+
+#if WOLFSSL_GENERAL_ALIGNMENT > 0
+    if (align)
+        outputBuffer->offset = align - hdrSz;
+    else
+#endif
+        outputBuffer->offset = 0;
+
+    outputBuffer->buffer = tmp;
+    outputBuffer->dynamicFlag = 1;
+    outputBuffer->bufferSize = size + outputBuffer->length;
+    return 0;
+}
+#endif
 
 /* returns the current location in the output buffer to start writing to */
 byte* GetOutputBuffer(WOLFSSL* ssl)
@@ -22210,6 +22289,7 @@ int ProcessReplyEx(WOLFSSL* ssl, int allowSocketErr)
                         #endif
                         }
                     #endif
+                #ifndef WOLFSSL_RW_THREADED
                     #ifdef WOLFSSL_TLS13
                         if (ssl->keys.keyUpdateRespond) {
                             WOLFSSL_MSG("No KeyUpdate from peer seen");
@@ -22217,6 +22297,7 @@ int ProcessReplyEx(WOLFSSL* ssl, int allowSocketErr)
                             return SANITY_MSG_E;
                         }
                     #endif
+                #endif
                     if ((ret = DoApplicationData(ssl,
                                                 ssl->buffers.inputBuffer.buffer,
                                                 &ssl->buffers.inputBuffer.idx,
@@ -23187,6 +23268,29 @@ int BuildMessage(WOLFSSL* ssl, byte* output, int outSz, const byte* input,
                         ssl->keys.dtls_prev_sequence_number_lo;
             }
     #endif
+
+#ifdef WOLFSSL_THREADED_CRYPT
+    if (asyncOkay) {
+        WOLFSSL_MSG("Not encrypting\n");
+        /* make sure build message state is reset */
+        ssl->options.buildMsgState = BUILD_MSG_BEGIN;
+
+        /* return sz on success */
+        if (ret == 0) {
+            ret = args->sz;
+        }
+        else {
+            WOLFSSL_ERROR_VERBOSE(ret);
+        }
+
+        /* Final cleanup */
+        FreeBuildMsgArgs(ssl, args);
+
+        return ret;
+    }
+    else
+#endif
+    {
     #if defined(HAVE_ENCRYPT_THEN_MAC) && !defined(WOLFSSL_AEAD_ONLY)
             if (ssl->options.startedETMWrite) {
                 ret = Encrypt(ssl, output + args->headerSz,
@@ -23209,6 +23313,7 @@ int BuildMessage(WOLFSSL* ssl, byte* output, int outSz, const byte* input,
                 ssl->keys.dtls_sequence_number_lo = dtls_sequence_number_lo;
             }
     #endif
+    }
             }
 
             if (ret != 0) {
@@ -24636,6 +24741,50 @@ static int CheckTLS13AEADSendLimit(WOLFSSL* ssl)
 }
 #endif /* WOLFSSL_TLS13 && !WOLFSSL_TLS13_IGNORE_AEAD_LIMITS */
 
+#ifdef WOLFSSL_THREADED_CRYPT
+int SendAsyncData(WOLFSSL* ssl)
+{
+    int i;
+
+    for (i = 0; i < WOLFSSL_THREADED_CRYPT_CNT; i++) {
+        ThreadCrypt* encrypt = &ssl->buffers.encrypt[i];
+
+        if (encrypt->done) {
+            int error;
+
+            GrowOutputBuffer(ssl, encrypt->buffer.length);
+            XMEMCPY(ssl->buffers.outputBuffer.buffer, encrypt->buffer.buffer,
+                encrypt->buffer.length);
+            ssl->buffers.outputBuffer.length = encrypt->buffer.length;
+            ssl->buffers.outputBuffer.idx = 0;
+            encrypt->done = 0;
+            encrypt->avail = 1;
+            if ((error = SendBuffered(ssl)) < 0) {
+                ssl->error = error;
+                WOLFSSL_ERROR(ssl->error);
+                /* store for next call if WANT_WRITE or user embedSend() that
+                   doesn't present like WANT_WRITE */
+                ssl->buffers.plainSz  = encrypt->buffer.length;
+                ssl->buffers.prevSent = encrypt->buffer.length;
+                if (ssl->error == WC_NO_ERR_TRACE(SOCKET_ERROR_E) &&
+                        (ssl->options.connReset || ssl->options.isClosed)) {
+                    return SOCKET_PEER_CLOSED_E;  /* peer reset or closed */
+                }
+                return ssl->error;
+            }
+
+            /* only one message per attempt */
+            if (ssl->options.partialWrite == 1) {
+                WOLFSSL_MSG("Partial Write on, only sending one record");
+                break;
+            }
+        }
+    }
+
+    return 0;
+}
+#endif
+
 /**
  * ssl_in_handshake():
  * Invoked in wolfSSL_read/wolfSSL_write to check if wolfSSL_negotiate() is
@@ -24690,18 +24839,20 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
 #if defined(WOLFSSL_EARLY_DATA) && defined(WOLFSSL_EARLY_DATA_GROUP)
     int groupMsgs = 0;
 #endif
+    int error = ssl->error;
 
-    if (ssl->error == WC_NO_ERR_TRACE(WANT_WRITE)
+    if (error == WC_NO_ERR_TRACE(WANT_WRITE)
     #ifdef WOLFSSL_ASYNC_CRYPT
-        || ssl->error == WC_NO_ERR_TRACE(WC_PENDING_E)
+        || error == WC_NO_ERR_TRACE(WC_PENDING_E)
     #endif
     ) {
+        error = 0;
         ssl->error = 0;
     }
 
     /* don't allow write after decrypt or mac error */
-    if (ssl->error == WC_NO_ERR_TRACE(VERIFY_MAC_ERROR) ||
-        ssl->error == WC_NO_ERR_TRACE(DECRYPT_ERROR)) {
+    if (error == WC_NO_ERR_TRACE(VERIFY_MAC_ERROR) ||
+        error == WC_NO_ERR_TRACE(DECRYPT_ERROR)) {
         /* For DTLS allow these possible errors and allow the session
             to continue despite them */
         if (ssl->options.dtls) {
@@ -24744,10 +24895,33 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
                 return WOLFSSL_CBIO_ERR_WANT_WRITE;
             }
         #endif
-            return  err;
+            return err;
         }
     }
 
+#ifdef WOLFSSL_RW_THREADED
+#ifdef WOLFSSL_DTLS13
+    if (ssl->options.dtls) {
+        /* Dtls13DoScheduledWork(ssl) may return WANT_WRITE */
+        if ((error = Dtls13DoScheduledWork(ssl)) < 0) {
+            ssl->error = error;
+            WOLFSSL_ERROR(error);
+            return error;
+        }
+    }
+#endif /* WOLFSSL_DTLS13 */
+#ifdef WOLFSSL_TLS13
+    if (ssl->options.sendKeyUpdate) {
+        ssl->options.sendKeyUpdate = 0;
+        ret = SendTls13KeyUpdate(ssl);
+        if (ret != 0) {
+            ssl->error = BUILD_MSG_ERROR;
+            return WOLFSSL_FATAL_ERROR;
+        }
+    }
+#endif
+#endif
+
     /* last time system socket output buffer was full, try again to send */
     if (ssl->buffers.outputBuffer.length > 0
     #if defined(WOLFSSL_EARLY_DATA) && defined(WOLFSSL_EARLY_DATA_GROUP)
@@ -24755,15 +24929,16 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
     #endif
         ) {
         WOLFSSL_MSG("output buffer was full, trying to send again");
-        if ( (ssl->error = SendBuffered(ssl)) < 0) {
-            WOLFSSL_ERROR(ssl->error);
-            if (ssl->error == WC_NO_ERR_TRACE(SOCKET_ERROR_E) &&
-                (ssl->options.connReset || ssl->options.isClosed)) {
-                ssl->error = SOCKET_PEER_CLOSED_E;
-                WOLFSSL_ERROR(ssl->error);
+        if ( (error = SendBuffered(ssl)) < 0) {
+            WOLFSSL_ERROR(error);
+            if (error == WC_NO_ERR_TRACE(SOCKET_ERROR_E) &&
+                    (ssl->options.connReset || ssl->options.isClosed)) {
+                error = SOCKET_PEER_CLOSED_E;
+                ssl->error = error;
+                WOLFSSL_ERROR(error);
                 return 0;  /* peer reset or closed */
             }
-            return ssl->error;
+            return (ssl->error = error);
         }
         else {
             /* advance sent to previous sent + plain size just sent */
@@ -24772,7 +24947,7 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
 
             if (sent > sz) {
                 WOLFSSL_MSG("error: write() after WANT_WRITE with short size");
-                return ssl->error = BAD_FUNC_ARG;
+                return (ssl->error = BAD_FUNC_ARG);
             }
         }
     }
@@ -24783,6 +24958,19 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
         return WOLFSSL_FATAL_ERROR;
     }
 
+#ifdef WOLFSSL_THREADED_CRYPT
+    ret = SendAsyncData(ssl);
+    if (ret != 0) {
+        ssl->error = ret;
+        return WOLFSSL_FATAL_ERROR;
+    }
+    if (ssl->dtls13WaitKeyUpdateAck) {
+        ret = DoDtls13KeyUpdateAck(ssl);
+        if (ret != 0)
+            return ret;
+    }
+#endif
+
     for (;;) {
         byte* out;
         byte* sendBuffer = (byte*)data + sent;  /* may switch on comp */
@@ -24791,6 +24979,10 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
 #ifdef HAVE_LIBZ
         byte  comp[MAX_RECORD_SIZE + MAX_COMP_EXTRA];
 #endif
+#ifdef WOLFSSL_THREADED_CRYPT
+        int i;
+        ThreadCrypt* encrypt = NULL;
+#endif
 
 #if defined(WOLFSSL_TLS13) && !defined(WOLFSSL_TLS13_IGNORE_AEAD_LIMITS)
         if (IsAtLeastTLSv1_3(ssl->version)) {
@@ -24855,9 +25047,10 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
 
 #if defined(WOLFSSL_DTLS) && !defined(WOLFSSL_NO_DTLS_SIZE_CHECK)
         if (ssl->options.dtls && (buffSz < sz - sent)) {
-            ssl->error = DTLS_SIZE_ERROR;
-            WOLFSSL_ERROR(ssl->error);
-            return ssl->error;
+            error = DTLS_SIZE_ERROR;
+            ssl->error = error;
+            WOLFSSL_ERROR(error);
+            return error;
         }
 #endif
         outputSz = buffSz + COMP_EXTRA + DTLS_RECORD_HEADER_SZ;
@@ -24874,10 +25067,33 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
 
         /* check for available size */
         if ((ret = CheckAvailableSize(ssl, outputSz)) != 0)
-            return ssl->error = ret;
+            return (ssl->error = ret);
 
         /* get output buffer */
+#ifndef WOLFSSL_THREADED_CRYPT
         out = GetOutputBuffer(ssl);
+#else
+        do {
+            for (i = 0; i < WOLFSSL_THREADED_CRYPT_CNT; i++) {
+                if (ssl->buffers.encrypt[i].avail) {
+                    encrypt = &ssl->buffers.encrypt[i];
+                    break;
+                }
+            }
+            if (encrypt == NULL) {
+                ret = SendAsyncData(ssl);
+                if (ret != 0) {
+                    ssl->error = ret;
+                    return WOLFSSL_FATAL_ERROR;
+                }
+            }
+        }
+        while (encrypt == NULL);
+        encrypt->done = 0;
+        encrypt->avail = 0;
+        GrowAnOutputBuffer(ssl, &encrypt->buffer, outputSz);
+        out = encrypt->buffer.buffer;
+#endif
 
 #ifdef HAVE_LIBZ
         if (ssl->options.usingCompression) {
@@ -24921,21 +25137,70 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
 #ifdef WOLFSSL_ASYNC_CRYPT
         FreeAsyncCtx(ssl, 0);
 #endif
+#ifdef WOLFSSL_THREADED_CRYPT
+        if (!encrypt->init) {
+            SetKeys(&encrypt->encrypt, NULL, &ssl->keys, &ssl->specs,
+                ssl->options.side, ssl->heap, ssl->devId, ssl->rng,
+                ssl->options.tls1_3);
+            encrypt->init = 1;
+        }
+        encrypt->buffer.length = sendSz;
+        encrypt->offset = RECORD_HEADER_SZ;
+        if (ssl->options.dtls) {
+            encrypt->offset += DTLS_RECORD_EXTRA;
+        }
+        encrypt->cryptLen = outputSz - encrypt->offset;
+    #ifdef HAVE_TRUNCATED_HMAC
+        if (ssl->truncated_hmac) {
+            encrypt->cryptLen -= min(TRUNCATED_HMAC_SZ, ssl->specs.hash_size);
+        }
+        else
+    #endif
+        {
+            encrypt->cryptLen -= ssl->specs.hash_size;
+        }
+
+#if !defined(NO_PUBLIC_GCM_SET_IV) && \
+    ((defined(HAVE_FIPS) || defined(HAVE_SELFTEST)) && \
+    (!defined(HAVE_FIPS_VERSION) || (HAVE_FIPS_VERSION < 2)))
+        XMEMCPY(encrypt->nonce, ssl->keys.aead_enc_imp_IV, AESGCM_IMP_IV_SZ);
+        XMEMCPY(encrypt->nonce + AESGCM_IMP_IV_SZ, ssl->keys.aead_exp_IV,
+            AESGCM_EXP_IV_SZ);
+#endif
+        XMEMSET(encrypt->additional, 0, AEAD_AUTH_DATA_SZ);
+        WriteSEQ(ssl, CUR_ORDER, encrypt->additional);
+        XMEMCPY(encrypt->additional + AEAD_TYPE_OFFSET, encrypt->buffer.buffer,
+            3);
+        c16toa(sendSz - encrypt->offset - AESGCM_EXP_IV_SZ -
+            ssl->specs.aead_mac_size, encrypt->additional + AEAD_LEN_OFFSET);
+
+    #ifdef WOLFSSL_DTLS
+        if (ssl->options.dtls)
+            DtlsSEQIncrement(ssl, CUR_ORDER);
+    #endif
+
+        if (encrypt->signal != NULL) {
+            encrypt->signal(encrypt->signalCtx, ssl);
+        }
+        return sendSz;
+#else
         ssl->buffers.outputBuffer.length += (word32)sendSz;
 
-        if ( (ssl->error = SendBuffered(ssl)) < 0) {
-            WOLFSSL_ERROR(ssl->error);
+        if ( (error = SendBuffered(ssl)) < 0) {
+            ssl->error = error;
+            WOLFSSL_ERROR(error);
             /* store for next call if WANT_WRITE or user embedSend() that
                doesn't present like WANT_WRITE */
             ssl->buffers.plainSz  = buffSz;
             ssl->buffers.prevSent = sent;
-            if (ssl->error == WC_NO_ERR_TRACE(SOCKET_ERROR_E) &&
-                (ssl->options.connReset || ssl->options.isClosed)) {
+            if (error == WC_NO_ERR_TRACE(SOCKET_ERROR_E) &&
+                    (ssl->options.connReset || ssl->options.isClosed)) {
+                error = SOCKET_PEER_CLOSED_E;
                 ssl->error = SOCKET_PEER_CLOSED_E;
-                WOLFSSL_ERROR(ssl->error);
+                WOLFSSL_ERROR(error);
                 return 0;  /* peer reset or closed */
             }
-            return ssl->error;
+            return error;
         }
 
         sent += buffSz;
@@ -24945,6 +25210,7 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
             WOLFSSL_MSG("Partial Write on, only sending one record");
             break;
         }
+#endif
     }
 
     return sent;
@@ -24954,13 +25220,14 @@ int SendData(WOLFSSL* ssl, const void* data, int sz)
 int ReceiveData(WOLFSSL* ssl, byte* output, int sz, int peek)
 {
     int size;
+    int error = ssl->error;
 
     WOLFSSL_ENTER("ReceiveData");
 
     /* reset error state */
-    if (ssl->error == WC_NO_ERR_TRACE(WANT_READ) ||
-        ssl->error == WOLFSSL_ERROR_WANT_READ)
-    {
+    if (error == WC_NO_ERR_TRACE(WANT_READ) ||
+        error == WOLFSSL_ERROR_WANT_READ) {
+        error = 0;
         ssl->error = 0;
     }
 
@@ -24968,25 +25235,26 @@ int ReceiveData(WOLFSSL* ssl, byte* output, int sz, int peek)
     if (ssl->options.dtls) {
         /* In DTLS mode, we forgive some errors and allow the session
          * to continue despite them. */
-        if (ssl->error == WC_NO_ERR_TRACE(VERIFY_MAC_ERROR) ||
-            ssl->error == WC_NO_ERR_TRACE(DECRYPT_ERROR) ||
-            ssl->error == WC_NO_ERR_TRACE(DTLS_SIZE_ERROR)) {
+        if (error == WC_NO_ERR_TRACE(VERIFY_MAC_ERROR) ||
+            error == WC_NO_ERR_TRACE(DECRYPT_ERROR) ||
+            error == WC_NO_ERR_TRACE(DTLS_SIZE_ERROR)) {
 
+            error = 0;
             ssl->error = 0;
         }
     }
 #endif /* WOLFSSL_DTLS */
 
-    if (ssl->error != 0 && ssl->error != WC_NO_ERR_TRACE(WANT_WRITE)
+    if (error != 0 && error != WC_NO_ERR_TRACE(WANT_WRITE)
 #ifdef WOLFSSL_ASYNC_CRYPT
-            && ssl->error != WC_NO_ERR_TRACE(WC_PENDING_E)
+            && error != WC_NO_ERR_TRACE(WC_PENDING_E)
 #endif
 #if defined(HAVE_SECURE_RENEGOTIATION) || defined(WOLFSSL_DTLS13)
-            && ssl->error != WC_NO_ERR_TRACE(APP_DATA_READY)
+            && error != WC_NO_ERR_TRACE(APP_DATA_READY)
 #endif
     ) {
         WOLFSSL_MSG("User calling wolfSSL_read in error state, not allowed");
-        return ssl->error;
+        return error;
     }
 
 #ifdef WOLFSSL_EARLY_DATA
@@ -25024,32 +25292,39 @@ int ReceiveData(WOLFSSL* ssl, byte* output, int sz, int peek)
 #endif
 
     while (ssl->buffers.clearOutputBuffer.length == 0) {
-        if ( (ssl->error = ProcessReply(ssl)) < 0) {
-            if (ssl->error == WC_NO_ERR_TRACE(ZERO_RETURN)) {
+        if ( (error = ProcessReply(ssl)) < 0) {
+            if (error == WC_NO_ERR_TRACE(ZERO_RETURN)) {
+                ssl->error = error;
                 WOLFSSL_MSG("Zero return, no more data coming");
                 return 0; /* no more data coming */
             }
-            if (ssl->error == WC_NO_ERR_TRACE(SOCKET_ERROR_E)) {
+            if (error == WC_NO_ERR_TRACE(SOCKET_ERROR_E)) {
                 if (ssl->options.connReset || ssl->options.isClosed) {
                     WOLFSSL_MSG("Peer reset or closed, connection done");
-                    ssl->error = SOCKET_PEER_CLOSED_E;
-                    WOLFSSL_ERROR(ssl->error);
+                    error = SOCKET_PEER_CLOSED_E;
+                    ssl->error = error;
+                    WOLFSSL_ERROR(error);
                     return 0; /* peer reset or closed */
                 }
             }
-            WOLFSSL_ERROR(ssl->error);
-            return ssl->error;
+            ssl->error = error;
+            WOLFSSL_ERROR(error);
+            return error;
         }
 
-#ifdef WOLFSSL_DTLS13
+#ifndef WOLFSSL_RW_THREADED
+    #ifdef WOLFSSL_DTLS13
         if (ssl->options.dtls) {
             /* Dtls13DoScheduledWork(ssl) may return WANT_WRITE */
-            if ((ssl->error = Dtls13DoScheduledWork(ssl)) < 0) {
-                WOLFSSL_ERROR(ssl->error);
-                return ssl->error;
+            if ((error = Dtls13DoScheduledWork(ssl)) < 0) {
+                ssl->error = error;
+                WOLFSSL_ERROR(error);
+                return error;
             }
         }
-#endif /* WOLFSSL_DTLS13 */
+    #endif /* WOLFSSL_DTLS13 */
+#endif
+
         #ifdef HAVE_SECURE_RENEGOTIATION
             if (ssl->secure_renegotiation &&
                 ssl->secure_renegotiation->startScr) {
diff --git a/src/keys.c b/src/keys.c
index 3123a610e0..b13fbdf5b8 100644
--- a/src/keys.c
+++ b/src/keys.c
@@ -2371,7 +2371,7 @@ static int SetPrefix(byte* sha_input, int idx)
 #endif
 
 
-static int SetKeys(Ciphers* enc, Ciphers* dec, Keys* keys, CipherSpecs* specs,
+int SetKeys(Ciphers* enc, Ciphers* dec, Keys* keys, CipherSpecs* specs,
                    int side, void* heap, int devId, WC_RNG* rng, int tls13)
 {
     (void)rng;
diff --git a/src/ssl.c b/src/ssl.c
index b19d334009..2fe5e93d99 100644
--- a/src/ssl.c
+++ b/src/ssl.c
@@ -23672,7 +23672,86 @@ wolfSSL_CTX_keylog_cb_func wolfSSL_CTX_get_keylog_callback(
 
 #endif /* OPENSSL_EXTRA */
 
-#ifndef NO_CERTS
+#ifdef WOLFSSL_THREADED_CRYPT
+int wolfSSL_AsyncEncryptReady(WOLFSSL* ssl, int idx)
+{
+    ThreadCrypt* encrypt;
+
+    if (ssl == NULL) {
+        return 0;
+    }
+
+    encrypt = &ssl->buffers.encrypt[idx];
+    return (encrypt->avail == 0) && (encrypt->done == 0);
+}
+
+int wolfSSL_AsyncEncryptStop(WOLFSSL* ssl, int idx)
+{
+    ThreadCrypt* encrypt;
+
+    if (ssl == NULL) {
+        return 1;
+    }
+
+    encrypt = &ssl->buffers.encrypt[idx];
+    return encrypt->stop;
+}
+
+int wolfSSL_AsyncEncrypt(WOLFSSL* ssl, int idx)
+{
+    int ret = WC_NO_ERR_TRACE(NOT_COMPILED_IN);
+    ThreadCrypt* encrypt = &ssl->buffers.encrypt[idx];
+
+    if (ssl->specs.bulk_cipher_algorithm == wolfssl_aes_gcm) {
+        unsigned char* out = encrypt->buffer.buffer + encrypt->offset;
+        unsigned char* input = encrypt->buffer.buffer + encrypt->offset;
+        word32 encSz = encrypt->buffer.length - encrypt->offset;
+
+        ret =
+#if !defined(NO_GCM_ENCRYPT_EXTRA) && \
+    ((!defined(HAVE_FIPS) && !defined(HAVE_SELFTEST)) || \
+    (defined(HAVE_FIPS_VERSION) && (HAVE_FIPS_VERSION >= 2)))
+              wc_AesGcmEncrypt_ex
+#else
+              wc_AesGcmEncrypt
+#endif
+              (encrypt->encrypt.aes,
+               out + AESGCM_EXP_IV_SZ, input + AESGCM_EXP_IV_SZ,
+               encSz - AESGCM_EXP_IV_SZ - ssl->specs.aead_mac_size,
+               encrypt->nonce, AESGCM_NONCE_SZ,
+               out + encSz - ssl->specs.aead_mac_size,
+               ssl->specs.aead_mac_size,
+               encrypt->additional, AEAD_AUTH_DATA_SZ);
+#if !defined(NO_PUBLIC_GCM_SET_IV) && \
+    ((!defined(HAVE_FIPS) && !defined(HAVE_SELFTEST)) || \
+    (defined(HAVE_FIPS_VERSION) && (HAVE_FIPS_VERSION >= 2)))
+        XMEMCPY(out, encrypt->nonce + AESGCM_IMP_IV_SZ, AESGCM_EXP_IV_SZ);
+#endif
+        encrypt->done = 1;
+    }
+
+    return ret;
+}
+
+int wolfSSL_AsyncEncryptSetSignal(WOLFSSL* ssl, int idx,
+    WOLFSSL_THREAD_SIGNAL signal, void* ctx)
+{
+    int ret = 0;
+
+    if (ssl == NULL) {
+        ret = BAD_FUNC_ARG;
+    }
+    else {
+        ssl->buffers.encrypt[idx].signal = signal;
+        ssl->buffers.encrypt[idx].signalCtx = ctx;
+    }
+
+    return ret;
+}
+#endif
+
+
+#ifndef NO_CERT
 #define WOLFSSL_X509_INCLUDED
 #include "src/x509.c"
 #endif
diff --git a/src/tls13.c b/src/tls13.c
index 6e24d2da4d..90e4568f40 100644
--- a/src/tls13.c
+++ b/src/tls13.c
@@ -11210,7 +11210,7 @@ static int SendTls13Finished(WOLFSSL* ssl)
  * ssl  The SSL/TLS object.
  * returns 0 on success, otherwise failure.
  */
-static int SendTls13KeyUpdate(WOLFSSL* ssl)
+int SendTls13KeyUpdate(WOLFSSL* ssl)
 {
     byte*  input;
     byte*  output;
@@ -11387,7 +11387,12 @@ static int DoTls13KeyUpdate(WOLFSSL* ssl, const byte* input, word32* inOutIdx,
         }
 #endif /* WOLFSSL_DTLS13 */
 
+#ifndef WOLFSSL_RW_THREADED
         return SendTls13KeyUpdate(ssl);
+#else
+        ssl->options.sendKeyUpdate = 1;
+        return 0;
+#endif
     }
 
     WOLFSSL_LEAVE("DoTls13KeyUpdate", ret);
diff --git a/src/wolfio.c b/src/wolfio.c
index a36ff53bd6..a632ff8431 100644
--- a/src/wolfio.c
+++ b/src/wolfio.c
@@ -650,6 +650,7 @@ int EmbedReceiveFrom(WOLFSSL *ssl, char *buf, int sz, void *ctx)
 #elif !defined(DTLS_RECEIVEFROM_NO_TIMEOUT_ON_INVALID_PEER)
     word32 invalidPeerPackets = 0;
 #endif
+    int newPeer = 0;
 
     WOLFSSL_ENTER("EmbedReceiveFrom");
 
@@ -677,8 +678,13 @@ int EmbedReceiveFrom(WOLFSSL *ssl, char *buf, int sz, void *ctx)
                 dtlsCtx->peer.bufSz = sizeof(SOCKADDR_S);
             else
                 dtlsCtx->peer.bufSz = 0;
+            newPeer = 1;
+            peer = (SOCKADDR_S*)dtlsCtx->peer.sa;
+        }
+        else {
+            peer = &lclPeer;
+            XMEMCPY(peer, (SOCKADDR_S*)dtlsCtx->peer.sa, sizeof(lclPeer));
         }
-        peer = (SOCKADDR_S*)dtlsCtx->peer.sa;
         peerSz = dtlsCtx->peer.bufSz;
     }
 
@@ -688,9 +694,20 @@ int EmbedReceiveFrom(WOLFSSL *ssl, char *buf, int sz, void *ctx)
 
 #ifdef WOLFSSL_DTLS13
     if (ssl->options.dtls && IsAtLeastTLSv1_3(ssl->version)) {
-        doDtlsTimeout =
-            doDtlsTimeout || ssl->dtls13Rtx.rtxRecords != NULL ||
+        doDtlsTimeout = doDtlsTimeout || ssl->dtls13Rtx.rtxRecords != NULL;
+#ifdef WOLFSSL_RW_THREADED
+        {
+            int ret = wc_LockMutex(&ssl->dtls13Rtx.mutex);
+            if (ret < 0) {
+                return ret;
+            }
+        }
+#endif
+        doDtlsTimeout = doDtlsTimeout ||
             (ssl->dtls13FastTimeout && ssl->dtls13Rtx.seenRecords != NULL);
+#ifdef WOLFSSL_RW_THREADED
+        wc_UnLockMutex(&ssl->dtls13Rtx.mutex);
+#endif
     }
 #endif /* WOLFSSL_DTLS13 */
 
@@ -822,8 +839,16 @@ int EmbedReceiveFrom(WOLFSSL *ssl, char *buf, int sz, void *ctx)
             }
         }
         else {
-            /* Store size of saved address */
-            dtlsCtx->peer.sz = peerSz;
+            if (newPeer) {
+                /* Store size of saved address */
+                dtlsCtx->peer.sz = peerSz;
+            }
+#ifndef WOLFSSL_PEER_ADDRESS_CHANGES
+            else if ((dtlsCtx->peer.sz != (unsigned int)peerSz) ||
+                     (XMEMCMP(peer, dtlsCtx->peer.sa, peerSz) != 0)) {
+                return WOLFSSL_CBIO_ERR_GENERAL;
+            }
+#endif
         }
 #ifndef NO_ASN_TIME
         ssl->dtls_start_timeout = 0;
diff --git a/wolfssl/internal.h b/wolfssl/internal.h
index 2fe5633dc6..ff9c1230d1 100644
--- a/wolfssl/internal.h
+++ b/wolfssl/internal.h
@@ -2920,8 +2920,8 @@ typedef struct Keys {
     byte   encryptionOn;          /* true after change cipher spec */
     byte   decryptedCur;          /* only decrypt current record once */
 #ifdef WOLFSSL_TLS13
-    byte   updateResponseReq:1;   /* KeyUpdate response from peer required. */
-    byte   keyUpdateRespond:1;    /* KeyUpdate is to be responded to. */
+    byte   updateResponseReq;     /* KeyUpdate response from peer required. */
+    byte   keyUpdateRespond;      /* KeyUpdate is to be responded to. */
 #endif
 #ifdef WOLFSSL_RENESAS_TSIP_TLS
 
@@ -4744,10 +4744,34 @@ enum AcceptStateTls13 {
     TLS13_TICKET_SENT
 };
 
+#ifdef WOLFSSL_THREADED_CRYPT
+
+#include <pthread.h>
+
+typedef struct ThreadCrypt {
+    Ciphers encrypt;
+    bufferStatic buffer;
+    unsigned char nonce[AESGCM_NONCE_SZ];
+    unsigned char additional[AEAD_AUTH_DATA_SZ];
+    int init;
+    int offset;
+    int cryptLen;
+    int done;
+    int avail;
+    int stop;
+    WOLFSSL_THREAD_SIGNAL signal;
+    void*                 signalCtx;
+} ThreadCrypt;
+
+#endif
+
 /* buffers for struct WOLFSSL */
 typedef struct Buffers {
     bufferStatic    inputBuffer;
     bufferStatic    outputBuffer;
+#ifdef WOLFSSL_THREADED_CRYPT
+    ThreadCrypt     encrypt[WOLFSSL_THREADED_CRYPT_CNT];
+#endif
     buffer          domainName;            /* for client check */
     buffer          clearOutputBuffer;
     buffer          sig;                   /* signature data */
@@ -4901,7 +4925,6 @@ struct Options {
     word16            tls:1;              /* using TLS ? */
     word16            tls1_1:1;           /* using TLSv1.1+ ? */
     word16            tls1_3:1;           /* using TLSv1.3+ ? */
-    word16            seenUnifiedHdr:1;   /* received msg with unified header */
     word16            dtls:1;             /* using datagrams ? */
 #ifdef WOLFSSL_DTLS
     word16            dtlsStateful:1;     /* allow stateful processing ? */
@@ -4910,7 +4933,6 @@ struct Options {
     word16            isClosed:1;         /* if we consider conn closed */
     word16            closeNotify:1;      /* we've received a close notify */
     word16            sentNotify:1;       /* we've sent a close notify */
-    word16            shutdownDone:1;     /* we've completed a shutdown */
     word16            usingCompression:1; /* are we using compression */
     word16            haveRSA:1;          /* RSA available */
     word16            haveECC:1;          /* ECC available */
@@ -4958,7 +4980,6 @@ struct Options {
 #endif
     word16            dtlsUseNonblock:1;  /* are we using nonblocking socket */
     word16            dtlsHsRetain:1;     /* DTLS retaining HS data */
-    word16            haveMcast:1;        /* using multicast ? */
 #ifdef WOLFSSL_SCTP
     word16            dtlsSctp:1;         /* DTLS-over-SCTP mode */
 #endif
@@ -5011,8 +5032,6 @@ struct Options {
     word16            buildArgsSet:1;         /* buildArgs are set and need to
                                                * be free'd */
 #endif
-    word16            buildingMsg:1;      /* If set then we need to re-enter the
-                                           * handshake logic. */
 #ifdef WOLFSSL_DTLS13
     word16            dtls13SendMoreAcks:1;  /* Send more acks during the
                                               * handshake process */
@@ -5039,6 +5058,14 @@ struct Options {
 #if defined(HAVE_DANE)
     word16            useDANE:1;
 #endif /* HAVE_DANE */
+#ifdef WOLFSSL_DTLS
+    byte              haveMcast;          /* using multicast ? */
+#endif
+    byte              buildingMsg;        /* If set then we need to re-enter the
+                                           * handshake logic. */
+    byte              seenUnifiedHdr;     /* received msg with unified header */
+    byte              shutdownDone;       /* we've completed a shutdown */
+    byte              sendKeyUpdate;      /* Key Update to write */
 #if defined(HAVE_RPK)
     RpkConfig         rpkConfig;
     RpkState          rpkState;
@@ -5678,14 +5705,17 @@ typedef struct Dtls13RecordNumber {
 } Dtls13RecordNumber;
 
 typedef struct Dtls13Rtx {
-    enum Dtls13RtxFsmState state;
+#ifdef WOLFSSL_RW_THREADED
+    wolfSSL_Mutex mutex;
+#endif
+    enum Dtls13RtxFsmState state; /* Unused? */
     Dtls13RtxRecord *rtxRecords;
     Dtls13RtxRecord **rtxRecordTailPtr;
     Dtls13RecordNumber *seenRecords;
     word32 lastRtx;
-    byte triggeredRtxs;
-    byte sendAcks:1;
-    byte retransmit:1;
+    byte triggeredRtxs; /* Unused? */
+    byte sendAcks;
+    byte retransmit;
 } Dtls13Rtx;
 
 #endif /* WOLFSSL_DTLS13 */
@@ -5963,10 +5993,10 @@ struct WOLFSSL {
     /* used to store the message if it needs to be fragmented */
     buffer dtls13FragmentsBuffer;
     byte dtls13SendingFragments:1;
-    byte dtls13SendingAckOrRtx:1;
+    byte dtls13SendingAckOrRtx;
     byte dtls13FastTimeout:1;
-    byte dtls13WaitKeyUpdateAck:1;
-    byte dtls13DoKeyUpdate:1;
+    byte dtls13WaitKeyUpdateAck;
+    byte dtls13DoKeyUpdate;
     word32 dtls13MessageLength;
     word32 dtls13FragOffset;
     byte dtls13FragHandshakeType;
@@ -6423,6 +6453,9 @@ WOLFSSL_LOCAL int DoClientTicket_ex(const WOLFSSL* ssl, PreSharedKey* psk,
 WOLFSSL_LOCAL int DoClientTicket(WOLFSSL* ssl, const byte* input, word32 len);
 #endif /* HAVE_SESSION_TICKET */
 WOLFSSL_LOCAL int SendData(WOLFSSL* ssl, const void* data, int sz);
+#ifdef WOLFSSL_THREADED_CRYPT
+WOLFSSL_LOCAL int SendAsyncData(WOLFSSL* ssl);
+#endif
 #ifdef WOLFSSL_TLS13
 WOLFSSL_LOCAL int SendTls13ServerHello(WOLFSSL* ssl, byte extMsgType);
 #endif
@@ -6627,6 +6660,10 @@ WOLFSSL_LOCAL word32 MacSize(const WOLFSSL* ssl);
     WOLFSSL_LOCAL int SendServerHelloDone(WOLFSSL* ssl);
 #endif /* NO_WOLFSSL_SERVER */
 
+#ifdef WOLFSSL_TLS13
+    WOLFSSL_LOCAL int SendTls13KeyUpdate(WOLFSSL* ssl);
+#endif
+
 #ifdef WOLFSSL_DTLS
     WOLFSSL_LOCAL DtlsMsg* DtlsMsgNew(word32 sz, byte tx, void* heap);
     WOLFSSL_LOCAL void DtlsMsgDelete(DtlsMsg* item, void* heap);
@@ -6773,6 +6810,9 @@ enum encrypt_side {
     ENCRYPT_AND_DECRYPT_SIDE
 };
 
+WOLFSSL_LOCAL int SetKeys(Ciphers* enc, Ciphers* dec, Keys* keys,
+    CipherSpecs* specs, int side, void* heap, int devId, WC_RNG* rng,
+    int tls13);
 WOLFSSL_LOCAL int SetKeysSide(WOLFSSL* ssl, enum encrypt_side side);
 
 /* Set*Internal and Set*External functions */
@@ -6933,6 +6973,7 @@ WOLFSSL_LOCAL int Dtls13HandshakeAddHeader(WOLFSSL* ssl, byte* output,
     enum HandShakeType msg_type, word32 length);
 #define EE_MASK (0x3)
 WOLFSSL_LOCAL int Dtls13FragmentsContinue(WOLFSSL* ssl);
+WOLFSSL_LOCAL int DoDtls13KeyUpdateAck(WOLFSSL* ssl);
 WOLFSSL_LOCAL int DoDtls13Ack(WOLFSSL* ssl, const byte* input, word32 inputSize,
     word32* processedSize);
 WOLFSSL_LOCAL int Dtls13ReconstructEpochNumber(WOLFSSL* ssl, byte epochBits,
diff --git a/wolfssl/ssl.h b/wolfssl/ssl.h
index 288bccb8d9..ec6c08fb6f 100644
--- a/wolfssl/ssl.h
+++ b/wolfssl/ssl.h
@@ -3364,6 +3364,21 @@ WOLFSSL_API void  wolfSSL_CTX_SetEncryptMacCb(WOLFSSL_CTX* ctx, CallbackEncryptM
 WOLFSSL_API void  wolfSSL_SetEncryptMacCtx(WOLFSSL* ssl, void *ctx);
 WOLFSSL_API void* wolfSSL_GetEncryptMacCtx(WOLFSSL* ssl);
 
+#ifdef WOLFSSL_THREADED_CRYPT
+    #ifndef WOLFSSL_THREADED_CRYPT_CNT
+        #define WOLFSSL_THREADED_CRYPT_CNT  16
+    #endif
+
+typedef void (*WOLFSSL_THREAD_SIGNAL)(void* ctx, WOLFSSL* ssl);
+
+WOLFSSL_API int wolfSSL_AsyncEncryptReady(WOLFSSL* ssl, int idx);
+WOLFSSL_API int wolfSSL_AsyncEncryptStop(WOLFSSL* ssl, int idx);
+WOLFSSL_API int wolfSSL_AsyncEncrypt(WOLFSSL* ssl, int idx);
+WOLFSSL_API int wolfSSL_AsyncEncryptSetSignal(WOLFSSL* ssl, int idx,
+   WOLFSSL_THREAD_SIGNAL signal, void* ctx);
+#endif
+
+
 typedef int (*CallbackVerifyDecrypt)(WOLFSSL* ssl,
        unsigned char* decOut, const unsigned char* decIn,
        unsigned int decSz, int content, int verify, unsigned int* padSz,