diff --git a/simon-simd.cpp b/simon-simd.cpp
index 14461e31..ae322af3 100644
--- a/simon-simd.cpp
+++ b/simon-simd.cpp
@@ -234,8 +234,9 @@ inline void SIMON128_Dec_Block(uint8x16_t &block0, const word64 *subkeys, unsign
 
     if (rounds & 1)
     {
-        const uint64x2_t rk = vld1q_dup_u64(subkeys + rounds - 1);
         std::swap(x1, y1);
+        const uint64x2_t rk = vld1q_dup_u64(subkeys + rounds - 1);
+
         y1 = veorq_u64(veorq_u64(y1, rk), SIMON128_f(x1));
         rounds--;
     }
@@ -266,7 +267,7 @@ inline void SIMON128_Dec_6_Blocks(uint8x16_t &block0, uint8x16_t &block1,
     uint64x2_t x2 = UnpackLow64<uint64x2_t>(block2, block3);
     uint64x2_t y2 = UnpackHigh64<uint64x2_t>(block2, block3);
     uint64x2_t x3 = UnpackLow64<uint64x2_t>(block4, block5);
-    uint64x2_t y3 = UnpackHigh64<uint64x2_t>(block5, block5);
+    uint64x2_t y3 = UnpackHigh64<uint64x2_t>(block4, block5);
 
     x1 = Shuffle64(x1); y1 = Shuffle64(y1);
     x2 = Shuffle64(x2); y2 = Shuffle64(y2);
@@ -279,6 +280,7 @@ inline void SIMON128_Dec_6_Blocks(uint8x16_t &block0, uint8x16_t &block1,
 
         y1 = veorq_u64(veorq_u64(y1, rk), SIMON128_f(x1));
         y2 = veorq_u64(veorq_u64(y2, rk), SIMON128_f(x2));
+        y3 = veorq_u64(veorq_u64(y3, rk), SIMON128_f(x3));
         rounds--;
     }
 
diff --git a/simon.cpp b/simon.cpp
index a966a4ca..11530120 100644
--- a/simon.cpp
+++ b/simon.cpp
@@ -384,7 +384,7 @@ void SIMON128::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock
     OutBlock oblk(xorBlock, outBlock); oblk(m_wspace[2])(m_wspace[3]);
 }
 
-#if defined(CRYPTOPP_SIMON_ADVANCED_PROCESS_BLOCKS)
+#if defined(CRYPTOPP_SIMON64_ADVANCED_PROCESS_BLOCKS)
 size_t SIMON64::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks,
         byte *outBlocks, size_t length, word32 flags) const
 {
@@ -416,7 +416,9 @@ size_t SIMON64::Dec::AdvancedProcessBlocks(const byte *inBlocks, const byte *xor
 #endif
     return BlockTransformation::AdvancedProcessBlocks(inBlocks, xorBlocks, outBlocks, length, flags);
 }
+#endif  // CRYPTOPP_SIMON64_ADVANCED_PROCESS_BLOCKS
 
+#if defined(CRYPTOPP_SIMON128_ADVANCED_PROCESS_BLOCKS)
 size_t SIMON128::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks,
         byte *outBlocks, size_t length, word32 flags) const
 {
@@ -448,6 +450,6 @@ size_t SIMON128::Dec::AdvancedProcessBlocks(const byte *inBlocks, const byte *xo
 #endif
     return BlockTransformation::AdvancedProcessBlocks(inBlocks, xorBlocks, outBlocks, length, flags);
 }
-#endif
+#endif  // CRYPTOPP_SIMON128_ADVANCED_PROCESS_BLOCKS
 
 NAMESPACE_END
diff --git a/simon.h b/simon.h
index 48382072..2b47debb 100644
--- a/simon.h
+++ b/simon.h
@@ -16,8 +16,12 @@
 #include "seckey.h"
 #include "secblock.h"
 
+#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X86
+# define CRYPTOPP_SIMON64_ADVANCED_PROCESS_BLOCKS 1
+#endif
+
 #if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_ARM32 || CRYPTOPP_BOOL_ARM64
-# define CRYPTOPP_SIMON_ADVANCED_PROCESS_BLOCKS 1
+# define CRYPTOPP_SIMON128_ADVANCED_PROCESS_BLOCKS 1
 #endif
 
 NAMESPACE_BEGIN(CryptoPP)
@@ -94,7 +98,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SIMON_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SIMON64_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };
@@ -107,7 +111,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SIMON_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SIMON64_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };
@@ -152,7 +156,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SIMON_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SIMON128_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };
@@ -165,7 +169,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SIMON_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SIMON128_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };
diff --git a/speck-simd.cpp b/speck-simd.cpp
index c1f2b4cc..a63ce4c6 100644
--- a/speck-simd.cpp
+++ b/speck-simd.cpp
@@ -254,7 +254,7 @@ inline void SPECK128_Dec_6_Blocks(uint8x16_t &block0, uint8x16_t &block1,
     uint64x2_t x2 = UnpackLow64<uint64x2_t>(block2, block3);
     uint64x2_t y2 = UnpackHigh64<uint64x2_t>(block2, block3);
     uint64x2_t x3 = UnpackLow64<uint64x2_t>(block4, block5);
-    uint64x2_t y3 = UnpackHigh64<uint64x2_t>(block5, block5);
+    uint64x2_t y3 = UnpackHigh64<uint64x2_t>(block4, block5);
 
     x1 = Shuffle64(x1);
     y1 = Shuffle64(y1);
@@ -996,10 +996,6 @@ inline size_t SPECK64_AdvancedProcessBlocks_SSE41(F1 func1, F4 func4,
         }
     }
 
-    //inBlocks += inIncrement;
-    //xorBlocks += xorIncrement;
-    //outBlocks += outIncrement;
-
     while (length >= blockSize)
     {
         const word32* inPtr = reinterpret_cast<const word32*>(inBlocks);
diff --git a/speck.cpp b/speck.cpp
index f6762094..5acac044 100644
--- a/speck.cpp
+++ b/speck.cpp
@@ -364,7 +364,7 @@ void SPECK128::Dec::ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock
     OutBlock oblk(xorBlock, outBlock); oblk(m_wspace[2])(m_wspace[3]);
 }
 
-#if defined(CRYPTOPP_SPECK_ADVANCED_PROCESS_BLOCKS)
+#if defined(CRYPTOPP_SPECK64_ADVANCED_PROCESS_BLOCKS)
 size_t SPECK64::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks,
         byte *outBlocks, size_t length, word32 flags) const
 {
@@ -386,7 +386,9 @@ size_t SPECK64::Dec::AdvancedProcessBlocks(const byte *inBlocks, const byte *xor
 #endif
     return BlockTransformation::AdvancedProcessBlocks(inBlocks, xorBlocks, outBlocks, length, flags);
 }
+#endif  // CRYPTOPP_SPECK64_ADVANCED_PROCESS_BLOCKS
 
+#if defined(CRYPTOPP_SPECK128_ADVANCED_PROCESS_BLOCKS)
 size_t SPECK128::Enc::AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks,
         byte *outBlocks, size_t length, word32 flags) const
 {
@@ -418,6 +420,6 @@ size_t SPECK128::Dec::AdvancedProcessBlocks(const byte *inBlocks, const byte *xo
 #endif
     return BlockTransformation::AdvancedProcessBlocks(inBlocks, xorBlocks, outBlocks, length, flags);
 }
-#endif
+#endif  // CRYPTOPP_SPECK128_ADVANCED_PROCESS_BLOCKS
 
 NAMESPACE_END
diff --git a/speck.h b/speck.h
index f34488af..6571074e 100644
--- a/speck.h
+++ b/speck.h
@@ -17,7 +17,11 @@
 #include "secblock.h"
 
 #if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_ARM32 || CRYPTOPP_BOOL_ARM64
-# define CRYPTOPP_SPECK_ADVANCED_PROCESS_BLOCKS 1
+# define CRYPTOPP_SPECK64_ADVANCED_PROCESS_BLOCKS 1
+#endif
+
+#if CRYPTOPP_BOOL_X64 || CRYPTOPP_BOOL_X32 || CRYPTOPP_BOOL_X86 || CRYPTOPP_BOOL_ARM32 || CRYPTOPP_BOOL_ARM64
+# define CRYPTOPP_SPECK128_ADVANCED_PROCESS_BLOCKS 1
 #endif
 
 NAMESPACE_BEGIN(CryptoPP)
@@ -94,7 +98,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SPECK_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SPECK64_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };
@@ -107,7 +111,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SPECK_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SPECK64_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };
@@ -152,7 +156,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SPECK_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SPECK128_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };
@@ -165,7 +169,7 @@ public:
     {
     protected:
         void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const;
-#if CRYPTOPP_SPECK_ADVANCED_PROCESS_BLOCKS
+#if CRYPTOPP_SPECK128_ADVANCED_PROCESS_BLOCKS
         size_t AdvancedProcessBlocks(const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags) const;
 #endif
     };