diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c
index 15a6a122c..59907a3e0 100644
--- a/armsrc/iso14443a.c
+++ b/armsrc/iso14443a.c
@@ -2503,7 +2503,7 @@ void ReaderMifare(bool first_try, uint8_t block, uint8_t keytype ) {
 			if (nt_diff == 0  && first_try)
 				par_low = par[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
 
-			par_list[nt_diff] = SwapBits(par[0], 8);
+			par_list[nt_diff] = reflect8(par[0]);
 			ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;  // xor with NACK value to get keystream
 
 			// Test if the information is complete
diff --git a/armsrc/util.c b/armsrc/util.c
index 6c3c06a34..454050a6a 100644
--- a/armsrc/util.c
+++ b/armsrc/util.c
@@ -13,14 +13,19 @@ size_t nbytes(size_t nbits) {
 	return (nbits >> 3)+((nbits % 8) > 0);
 }
 
-uint32_t SwapBits(uint32_t value, int nrbits) {
+// Swap bit order on a uint32_t value.  Can be limited by 'b' just use say 8 bits reversal
+// note: function clears the rest of the bits.
+uint32_t SwapBits(uint32_t v, int b) {
 	uint32_t newvalue = 0;
-	for(int i = 0; i < nrbits; i++) {
-		newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i);
+	for(int i = 0; i < b; i++) {
+		newvalue ^= ((v >> i) & 1) << (b - 1 - i);
 	}
 	return newvalue;
 }
 
+uint8_t reflect8(uint8_t b) {
+	return ((b * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
+}
 /*
  ref  http://www.csm.ornl.gov/~dunigan/crc.html
  Returns the value v with the bottom b [0,32] bits reflected. 
diff --git a/armsrc/util.h b/armsrc/util.h
index c68a1d51a..32d5efcc5 100644
--- a/armsrc/util.h
+++ b/armsrc/util.h
@@ -42,6 +42,10 @@
 size_t nbytes(size_t nbits);
 uint32_t SwapBits(uint32_t value, int nrbits);
 uint32_t reflect(uint32_t v, int b);
+
+// dedicated 8bit reversal
+uint8_t reflect8(uint8_t b);
+
 void num_to_bytes(uint64_t n, size_t len, uint8_t* dest);
 uint64_t bytes_to_num(uint8_t* src, size_t len);
 void rol(uint8_t *data, const size_t len);
diff --git a/client/util.c b/client/util.c
index b555352cd..cd1039038 100644
--- a/client/util.c
+++ b/client/util.c
@@ -729,15 +729,18 @@ void rol(uint8_t *data, const size_t len){
     data[len-1] = first;
 }
 
-// Swap bit order on a uint32_t value.  Can be limited by nrbits just use say 8bits reversal
-// And clears the rest of the bits.
-uint32_t SwapBits(uint32_t value, int nrbits) {
+// Swap bit order on a uint32_t value.  Can be limited by 'b' just use say 8 bits reversal
+// note: function clears the rest of the bits.
+uint32_t SwapBits(uint32_t v, int b) {
 	uint32_t newvalue = 0;
-	for(int i = 0; i < nrbits; i++) {
-		newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i);
+	for(int i = 0; i < b; i++) {
+		newvalue ^= ((v >> i) & 1) << (b - 1 - i);
 	}
 	return newvalue;
 }
+uint8_t reflect8(uint8_t b) {
+	return ((b * 0x80200802ULL) & 0x0884422110ULL) * 0x0101010101ULL >> 32;
+}
 /*
  ref  http://www.csm.ornl.gov/~dunigan/crc.html
  Returns the value v with the bottom b [0,32] bits reflected. 
diff --git a/client/util.h b/client/util.h
index 17fbd7bcb..04cbf7d5b 100644
--- a/client/util.h
+++ b/client/util.h
@@ -204,6 +204,7 @@ extern uint32_t PackBits(uint8_t start, uint8_t len, uint8_t* bits);
 extern void rol(uint8_t *data, const size_t len);
 extern uint32_t SwapBits(uint32_t value, int nrbits);
 extern uint32_t reflect(uint32_t v, int b);
+extern uint8_t reflect8(uint8_t b);	// dedicated 8bit reversal
 extern uint64_t HornerScheme(uint64_t num, uint64_t divider, uint64_t factor);
 
 extern int num_CPUs(void);			// number of logical CPUs