diff --git a/common/crapto1/crapto1.c b/common/crapto1/crapto1.c
new file mode 100644
index 00000000..6a194c46
--- /dev/null
+++ b/common/crapto1/crapto1.c
@@ -0,0 +1,584 @@
+/*  crapto1.c
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor,
+	Boston, MA  02110-1301, US$
+
+	Copyright (C) 2008-2008 bla <blapost@gmail.com>
+*/
+#include "crapto1.h"
+#include <stdlib.h>
+#include <stdbool.h>
+
+#if !defined LOWMEM && defined __GNUC__
+static uint8_t filterlut[1 << 20];
+static void __attribute__((constructor)) fill_lut()
+{
+		uint32_t i;
+		for(i = 0; i < 1 << 20; ++i)
+				filterlut[i] = filter(i);
+}
+#define filter(x) (filterlut[(x) & 0xfffff])
+#endif
+
+
+
+typedef struct bucket {
+	uint32_t *head;
+	uint32_t *bp;
+} bucket_t;
+
+typedef bucket_t bucket_array_t[2][0x100];
+
+typedef struct bucket_info {
+	struct {
+		uint32_t *head, *tail;
+		} bucket_info[2][0x100];
+		uint32_t numbuckets;
+	} bucket_info_t;
+
+
+static void bucket_sort_intersect(uint32_t* const estart, uint32_t* const estop,
+								  uint32_t* const ostart, uint32_t* const ostop,
+								  bucket_info_t *bucket_info, bucket_array_t bucket)
+{
+	uint32_t *p1, *p2;
+	uint32_t *start[2];
+	uint32_t *stop[2];
+
+	start[0] = estart;
+	stop[0] = estop;
+	start[1] = ostart;
+	stop[1] = ostop;
+
+	// init buckets to be empty
+	for (uint32_t i = 0; i < 2; i++) {
+		for (uint32_t j = 0x00; j <= 0xff; j++) {
+			bucket[i][j].bp = bucket[i][j].head;
+		}
+	}
+
+	// sort the lists into the buckets based on the MSB (contribution bits)
+	for (uint32_t i = 0; i < 2; i++) {
+		for (p1 = start[i]; p1 <= stop[i]; p1++) {
+			uint32_t bucket_index = (*p1 & 0xff000000) >> 24;
+			*(bucket[i][bucket_index].bp++) = *p1;
+		}
+	}
+
+
+	// write back intersecting buckets as sorted list.
+	// fill in bucket_info with head and tail of the bucket contents in the list and number of non-empty buckets.
+	uint32_t nonempty_bucket;
+	for (uint32_t i = 0; i < 2; i++) {
+		p1 = start[i];
+		nonempty_bucket = 0;
+		for (uint32_t j = 0x00; j <= 0xff; j++) {
+			if (bucket[0][j].bp != bucket[0][j].head && bucket[1][j].bp != bucket[1][j].head) { // non-empty intersecting buckets only
+				bucket_info->bucket_info[i][nonempty_bucket].head = p1;
+				for (p2 = bucket[i][j].head; p2 < bucket[i][j].bp; *p1++ = *p2++);
+				bucket_info->bucket_info[i][nonempty_bucket].tail = p1 - 1;
+				nonempty_bucket++;
+			}
+		}
+		bucket_info->numbuckets = nonempty_bucket;
+		}
+}
+
+/** binsearch
+ * Binary search for the first occurence of *stop's MSB in sorted [start,stop]
+ */
+static inline uint32_t*
+binsearch(uint32_t *start, uint32_t *stop)
+{
+	uint32_t mid, val = *stop & 0xff000000;
+	while(start != stop)
+		if(start[mid = (stop - start) >> 1] > val)
+			stop = &start[mid];
+		else
+			start += mid + 1;
+
+	return start;
+}
+
+/** update_contribution
+ * helper, calculates the partial linear feedback contributions and puts in MSB
+ */
+static inline void
+update_contribution(uint32_t *item, const uint32_t mask1, const uint32_t mask2)
+{
+	uint32_t p = *item >> 25;
+
+	p = p << 1 | parity(*item & mask1);
+	p = p << 1 | parity(*item & mask2);
+	*item = p << 24 | (*item & 0xffffff);
+}
+
+/** extend_table
+ * using a bit of the keystream extend the table of possible lfsr states
+ */
+static inline void
+extend_table(uint32_t *tbl, uint32_t **end, int bit, int m1, int m2, uint32_t in)
+{
+	in <<= 24;
+
+	for(uint32_t *p = tbl; p <= *end; p++) {
+		*p <<= 1;
+		if(filter(*p) != filter(*p | 1)) {			 	// replace
+			*p |= filter(*p) ^ bit;
+			update_contribution(p, m1, m2);
+			*p ^= in;
+		} else if(filter(*p) == bit) {					// insert
+			*++*end = p[1];
+			p[1] = p[0] | 1;
+			update_contribution(p, m1, m2);
+			*p++ ^= in;
+			update_contribution(p, m1, m2);
+			*p ^= in;
+		} else {										// drop
+			*p-- = *(*end)--;
+		}
+	}
+
+}
+
+
+/** extend_table_simple
+ * using a bit of the keystream extend the table of possible lfsr states
+ */
+static inline void
+extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)
+{
+	for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)
+		if(filter(*tbl) ^ filter(*tbl | 1)) {	// replace
+			*tbl |= filter(*tbl) ^ bit;
+		} else if(filter(*tbl) == bit) {		// insert
+			*++*end = *++tbl;
+			*tbl = tbl[-1] | 1;
+		} else									// drop
+			*tbl-- = *(*end)--;
+}
+
+
+/** recover
+ * recursively narrow down the search space, 4 bits of keystream at a time
+ */
+static struct Crypto1State*
+recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks,
+	uint32_t *e_head, uint32_t *e_tail, uint32_t eks, int rem,
+	struct Crypto1State *sl, uint32_t in, bucket_array_t bucket)
+{
+	uint32_t *o, *e;
+	bucket_info_t bucket_info;
+
+	if(rem == -1) {
+		for(e = e_head; e <= e_tail; ++e) {
+			*e = *e << 1 ^ parity(*e & LF_POLY_EVEN) ^ !!(in & 4);
+			for(o = o_head; o <= o_tail; ++o, ++sl) {
+				sl->even = *o;
+				sl->odd = *e ^ parity(*o & LF_POLY_ODD);
+			}
+		}
+		sl->odd = sl->even = 0;
+		return sl;
+	}
+
+	for(uint32_t i = 0; i < 4 && rem--; i++) {
+		extend_table(o_head, &o_tail, (oks >>= 1) & 1,
+			LF_POLY_EVEN << 1 | 1, LF_POLY_ODD << 1, 0);
+		if(o_head > o_tail)
+			return sl;
+
+		extend_table(e_head, &e_tail, (eks >>= 1) & 1,
+			LF_POLY_ODD, LF_POLY_EVEN << 1 | 1, (in >>= 2) & 3);
+		if(e_head > e_tail)
+			return sl;
+	}
+
+	bucket_sort_intersect(e_head, e_tail, o_head, o_tail, &bucket_info, bucket);
+
+	for (int i = bucket_info.numbuckets - 1; i >= 0; i--) {
+		sl = recover(bucket_info.bucket_info[1][i].head, bucket_info.bucket_info[1][i].tail, oks,
+					 bucket_info.bucket_info[0][i].head, bucket_info.bucket_info[0][i].tail, eks,
+					 rem, sl, in, bucket);
+	}
+
+	return sl;
+}
+/** lfsr_recovery
+ * recover the state of the lfsr given 32 bits of the keystream
+ * additionally you can use the in parameter to specify the value
+ * that was fed into the lfsr at the time the keystream was generated
+ */
+struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
+{
+	struct Crypto1State *statelist;
+	uint32_t *odd_head = 0, *odd_tail = 0, oks = 0;
+	uint32_t *even_head = 0, *even_tail = 0, eks = 0;
+	int i;
+
+	// split the keystream into an odd and even part
+	for(i = 31; i >= 0; i -= 2)
+		oks = oks << 1 | BEBIT(ks2, i);
+	for(i = 30; i >= 0; i -= 2)
+ 		eks = eks << 1 | BEBIT(ks2, i);
+
+	odd_head = odd_tail = malloc(sizeof(uint32_t) << 21);
+	even_head = even_tail = malloc(sizeof(uint32_t) << 21);
+	statelist =  malloc(sizeof(struct Crypto1State) << 18);
+	if(!odd_tail-- || !even_tail-- || !statelist) {
+		goto out;
+	}
+	statelist->odd = statelist->even = 0;
+
+	// allocate memory for out of place bucket_sort
+	bucket_array_t bucket;
+	for (uint32_t i = 0; i < 2; i++)
+		for (uint32_t j = 0; j <= 0xff; j++) {
+			bucket[i][j].head = malloc(sizeof(uint32_t)<<14);
+			if (!bucket[i][j].head) {
+				goto out;
+			}
+		}
+
+
+	// initialize statelists: add all possible states which would result into the rightmost 2 bits of the keystream
+	for(i = 1 << 20; i >= 0; --i) {
+		if(filter(i) == (oks & 1))
+			*++odd_tail = i;
+		if(filter(i) == (eks & 1))
+			*++even_tail = i;
+	}
+
+	// extend the statelists. Look at the next 8 Bits of the keystream (4 Bit each odd and even):
+	for(i = 0; i < 4; i++) {
+		extend_table_simple(odd_head,  &odd_tail, (oks >>= 1) & 1);
+		extend_table_simple(even_head, &even_tail, (eks >>= 1) & 1);
+	}
+
+	// the statelists now contain all states which could have generated the last 10 Bits of the keystream.
+	// 22 bits to go to recover 32 bits in total. From now on, we need to take the "in"
+	// parameter into account.
+
+	in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00);		// Byte swapping
+
+	recover(odd_head, odd_tail, oks,
+		even_head, even_tail, eks, 11, statelist, in << 1, bucket);
+
+
+out:
+	free(odd_head);
+	free(even_head);
+	for (uint32_t i = 0; i < 2; i++)
+		for (uint32_t j = 0; j <= 0xff; j++)
+			free(bucket[i][j].head);
+
+	return statelist;
+}
+
+static const uint32_t S1[] = {     0x62141, 0x310A0, 0x18850, 0x0C428, 0x06214,
+	0x0310A, 0x85E30, 0xC69AD, 0x634D6, 0xB5CDE, 0xDE8DA, 0x6F46D, 0xB3C83,
+	0x59E41, 0xA8995, 0xD027F, 0x6813F, 0x3409F, 0x9E6FA};
+static const uint32_t S2[] = {  0x3A557B00, 0x5D2ABD80, 0x2E955EC0, 0x174AAF60,
+	0x0BA557B0, 0x05D2ABD8, 0x0449DE68, 0x048464B0, 0x42423258, 0x278192A8,
+	0x156042D0, 0x0AB02168, 0x43F89B30, 0x61FC4D98, 0x765EAD48, 0x7D8FDD20,
+	0x7EC7EE90, 0x7F63F748, 0x79117020};
+static const uint32_t T1[] = {
+	0x4F37D, 0x279BE, 0x97A6A, 0x4BD35, 0x25E9A, 0x12F4D, 0x097A6, 0x80D66,
+	0xC4006, 0x62003, 0xB56B4, 0x5AB5A, 0xA9318, 0xD0F39, 0x6879C, 0xB057B,
+	0x582BD, 0x2C15E, 0x160AF, 0x8F6E2, 0xC3DC4, 0xE5857, 0x72C2B, 0x39615,
+	0x98DBF, 0xC806A, 0xE0680, 0x70340, 0x381A0, 0x98665, 0x4C332, 0xA272C};
+static const uint32_t T2[] = {  0x3C88B810, 0x5E445C08, 0x2982A580, 0x14C152C0,
+	0x4A60A960, 0x253054B0, 0x52982A58, 0x2FEC9EA8, 0x1156C4D0, 0x08AB6268,
+	0x42F53AB0, 0x217A9D58, 0x161DC528, 0x0DAE6910, 0x46D73488, 0x25CB11C0,
+	0x52E588E0, 0x6972C470, 0x34B96238, 0x5CFC3A98, 0x28DE96C8, 0x12CFC0E0,
+	0x4967E070, 0x64B3F038, 0x74F97398, 0x7CDC3248, 0x38CE92A0, 0x1C674950,
+	0x0E33A4A8, 0x01B959D0, 0x40DCACE8, 0x26CEDDF0};
+static const uint32_t C1[] = { 0x846B5, 0x4235A, 0x211AD};
+static const uint32_t C2[] = { 0x1A822E0, 0x21A822E0, 0x21A822E0};
+/** Reverse 64 bits of keystream into possible cipher states
+ * Variation mentioned in the paper. Somewhat optimized version
+ */
+struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3)
+{
+	struct Crypto1State *statelist, *sl;
+	uint8_t oks[32], eks[32], hi[32];
+	uint32_t low = 0,  win = 0;
+	uint32_t *tail, table[1 << 16];
+	int i, j;
+
+	sl = statelist = malloc(sizeof(struct Crypto1State) << 4);
+	if(!sl)
+		return 0;
+	sl->odd = sl->even = 0;
+
+	for(i = 30; i >= 0; i -= 2) {
+		oks[i >> 1] = BIT(ks2, i ^ 24);
+		oks[16 + (i >> 1)] = BIT(ks3, i ^ 24);
+	}
+	for(i = 31; i >= 0; i -= 2) {
+		eks[i >> 1] = BIT(ks2, i ^ 24);
+		eks[16 + (i >> 1)] = BIT(ks3, i ^ 24);
+	}
+
+	for(i = 0xfffff; i >= 0; --i) {
+		if (filter(i) != oks[0])
+			continue;
+
+		*(tail = table) = i;
+		for(j = 1; tail >= table && j < 29; ++j)
+			extend_table_simple(table, &tail, oks[j]);
+
+		if(tail < table)
+			continue;
+
+		for(j = 0; j < 19; ++j)
+			low = low << 1 | parity(i & S1[j]);
+		for(j = 0; j < 32; ++j)
+			hi[j] = parity(i & T1[j]);
+
+		for(; tail >= table; --tail) {
+			for(j = 0; j < 3; ++j) {
+				*tail = *tail << 1;
+				*tail |= parity((i & C1[j]) ^ (*tail & C2[j]));
+				if(filter(*tail) != oks[29 + j])
+					goto continue2;
+			}
+
+			for(j = 0; j < 19; ++j)
+				win = win << 1 | parity(*tail & S2[j]);
+
+			win ^= low;
+			for(j = 0; j < 32; ++j) {
+				win = win << 1 ^ hi[j] ^ parity(*tail & T2[j]);
+				if(filter(win) != eks[j])
+					goto continue2;
+			}
+
+			*tail = *tail << 1 | parity(LF_POLY_EVEN & *tail);
+			sl->odd = *tail ^ parity(LF_POLY_ODD & win);
+			sl->even = win;
+			++sl;
+			sl->odd = sl->even = 0;
+			continue2:;
+		}
+	}
+	return statelist;
+}
+
+/** lfsr_rollback_bit
+ * Rollback the shift register in order to get previous states
+ */
+void lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)
+{
+	int out;
+	uint32_t tmp;
+
+	s->odd &= 0xffffff;
+	tmp = s->odd;
+	s->odd = s->even;
+	s->even = tmp;
+
+	out = s->even & 1;
+	out ^= LF_POLY_EVEN & (s->even >>= 1);
+	out ^= LF_POLY_ODD & s->odd;
+	out ^= !!in;
+	out ^= filter(s->odd) & !!fb;
+
+	s->even |= parity(out) << 23;
+}
+/** lfsr_rollback_byte
+ * Rollback the shift register in order to get previous states
+ */
+void lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)
+{
+	int i;
+	for (i = 7; i >= 0; --i)
+		lfsr_rollback_bit(s, BEBIT(in, i), fb);
+}
+/** lfsr_rollback_word
+ * Rollback the shift register in order to get previous states
+ */
+void lfsr_rollback_word(struct Crypto1State *s, uint32_t in, int fb)
+{
+	int i;
+	for (i = 31; i >= 0; --i)
+		lfsr_rollback_bit(s, BEBIT(in, i), fb);
+}
+
+/** nonce_distance
+ * x,y valid tag nonces, then prng_successor(x, nonce_distance(x, y)) = y
+ */
+static uint16_t *dist = 0;
+int nonce_distance(uint32_t from, uint32_t to)
+{
+	uint16_t x, i;
+	if(!dist) {
+		dist = malloc(2 << 16);
+		if(!dist)
+			return -1;
+		for (x = i = 1; i; ++i) {
+			dist[(x & 0xff) << 8 | x >> 8] = i;
+			x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;
+		}
+	}
+	return (65535 + dist[to >> 16] - dist[from >> 16]) % 65535;
+}
+
+
+static uint32_t fastfwd[2][8] = {
+	{ 0, 0x4BC53, 0xECB1, 0x450E2, 0x25E29, 0x6E27A, 0x2B298, 0x60ECB},
+	{ 0, 0x1D962, 0x4BC53, 0x56531, 0xECB1, 0x135D3, 0x450E2, 0x58980}};
+
+
+/** lfsr_prefix_ks
+ *
+ * Is an exported helper function from the common prefix attack
+ * Described in the "dark side" paper. It returns an -1 terminated array
+ * of possible partial(21 bit) secret state.
+ * The required keystream(ks) needs to contain the keystream that was used to
+ * encrypt the NACK which is observed when varying only the 4 last bits of Nr
+ * only correct iff [NR_3] ^ NR_3 does not depend on Nr_3
+ */
+uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)
+{
+	uint32_t *candidates = malloc(4 << 21);
+	uint32_t c,  entry;
+	int size, i;
+
+	if(!candidates)
+		return 0;
+
+	size = (1 << 21) - 1;
+	for(i = 0; i <= size; ++i)
+		candidates[i] = i;
+
+	for(c = 0;  c < 8; ++c)
+		for(i = 0;i <= size; ++i) {
+			entry = candidates[i] ^ fastfwd[isodd][c];
+
+			if(filter(entry >> 1) == BIT(ks[c], isodd))
+				if(filter(entry) == BIT(ks[c], isodd + 2))
+					continue;
+
+			candidates[i--] = candidates[size--];
+		}
+
+	candidates[size + 1] = -1;
+
+	return candidates;
+}
+
+/** brute_top
+ * helper function which eliminates possible secret states using parity bits
+ */
+static struct Crypto1State*
+brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8],
+		  uint32_t odd, uint32_t even, struct Crypto1State* sl)
+{
+	struct Crypto1State s;
+	uint32_t ks1, nr, ks2, rr, ks3, good, c;
+
+	bool no_par = true;
+	for (int i = 0; i < 8; i++) {
+		for (int j = 0; j < 8; j++) {
+			if (parities[i][j] != 0) {
+				no_par = false;
+				break;
+			}
+		}
+	}
+
+	for(c = 0; c < 8; ++c) {
+		s.odd = odd ^ fastfwd[1][c];
+		s.even = even ^ fastfwd[0][c];
+
+		lfsr_rollback_bit(&s, 0, 0);
+		lfsr_rollback_bit(&s, 0, 0);
+		lfsr_rollback_bit(&s, 0, 0);
+
+		lfsr_rollback_word(&s, 0, 0);
+		lfsr_rollback_word(&s, prefix | c << 5, 1);
+
+		sl->odd = s.odd;
+		sl->even = s.even;
+
+		if (no_par)
+			break;
+
+		ks1 = crypto1_word(&s, prefix | c << 5, 1);
+		ks2 = crypto1_word(&s,0,0);
+		ks3 = crypto1_word(&s, 0,0);
+		nr = ks1 ^ (prefix | c << 5);
+		rr = ks2 ^ rresp;
+
+		good = 1;
+		good &= parity(nr & 0x000000ff) ^ parities[c][3] ^ BIT(ks2, 24);
+		good &= parity(rr & 0xff000000) ^ parities[c][4] ^ BIT(ks2, 16);
+		good &= parity(rr & 0x00ff0000) ^ parities[c][5] ^ BIT(ks2,  8);
+		good &= parity(rr & 0x0000ff00) ^ parities[c][6] ^ BIT(ks2,  0);
+		good &= parity(rr & 0x000000ff) ^ parities[c][7] ^ BIT(ks3, 24);
+
+		if(!good)
+			return sl;
+	}
+
+	return ++sl;
+}
+
+
+/** lfsr_common_prefix
+ * Implentation of the common prefix attack.
+ * Requires the 28 bit constant prefix used as reader nonce (pfx)
+ * The reader response used (rr)
+ * The keystream used to encrypt the observed NACK's (ks)
+ * The parity bits (par)
+ * It returns a zero terminated list of possible cipher states after the
+ * tag nonce was fed in
+ */
+struct Crypto1State*
+lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8])
+{
+	struct Crypto1State *statelist, *s;
+	uint32_t *odd, *even, *o, *e, top;
+
+	odd = lfsr_prefix_ks(ks, 1);
+	even = lfsr_prefix_ks(ks, 0);
+
+	statelist = malloc((sizeof *statelist) << 21);	//how large should be?
+	if(!statelist || !odd || !even)
+	{
+				free(statelist);
+				free(odd);
+				free(even);
+				return 0;
+	}
+
+	s = statelist;
+	for(o = odd; *o != -1; ++o)
+		for(e = even; *e != -1; ++e)
+			for(top = 0; top < 64; ++top) {
+				*o = (*o & 0x1fffff) | (top << 21);
+				*e = (*e & 0x1fffff) | (top >> 3) << 21;
+				s = brute_top(pfx, rr, par, *o, *e, s);
+			}
+
+	s->odd = s->even = -1;
+	//printf("state count = %d\n",s-statelist);
+
+	free(odd);
+	free(even);
+
+	return statelist;
+}
diff --git a/common/crapto1/crapto1.h b/common/crapto1/crapto1.h
new file mode 100644
index 00000000..741d2008
--- /dev/null
+++ b/common/crapto1/crapto1.h
@@ -0,0 +1,98 @@
+/*  crapto1.h
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+    MA  02110-1301, US$
+
+    Copyright (C) 2008-2008 bla <blapost@gmail.com>
+*/
+#ifndef CRAPTO1_INCLUDED
+#define CRAPTO1_INCLUDED
+#include <stdint.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct Crypto1State {uint32_t odd, even;};
+#if defined(__arm__)
+void crypto1_create(struct Crypto1State *s, uint64_t key);
+#else
+struct Crypto1State *crypto1_create(uint64_t key);
+#endif
+void crypto1_destroy(struct Crypto1State*);
+void crypto1_get_lfsr(struct Crypto1State*, uint64_t*);
+uint8_t crypto1_bit(struct Crypto1State*, uint8_t, int);
+uint8_t crypto1_byte(struct Crypto1State*, uint8_t, int);
+uint32_t crypto1_word(struct Crypto1State*, uint32_t, int);
+uint32_t prng_successor(uint32_t x, uint32_t n);
+
+struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in);
+struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3);
+uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd);
+struct Crypto1State*
+lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]);
+
+
+void lfsr_rollback_bit(struct Crypto1State* s, uint32_t in, int fb);
+void lfsr_rollback_byte(struct Crypto1State* s, uint32_t in, int fb);
+void lfsr_rollback_word(struct Crypto1State* s, uint32_t in, int fb);
+int nonce_distance(uint32_t from, uint32_t to);
+#define FOREACH_VALID_NONCE(N, FILTER, FSIZE)\
+	uint32_t __n = 0,__M = 0, N = 0;\
+	int __i;\
+	for(; __n < 1 << 16; N = prng_successor(__M = ++__n, 16))\
+		for(__i = FSIZE - 1; __i >= 0; __i--)\
+			if(BIT(FILTER, __i) ^ parity(__M & 0xFF01))\
+				break;\
+			else if(__i)\
+				__M = prng_successor(__M, (__i == 7) ? 48 : 8);\
+			else 
+
+#define LF_POLY_ODD (0x29CE5C)
+#define LF_POLY_EVEN (0x870804)
+#define BIT(x, n) ((x) >> (n) & 1)
+#define BEBIT(x, n) BIT(x, (n) ^ 24)
+static inline int parity(uint32_t x)
+{
+#if !defined __i386__ || !defined __GNUC__
+	x ^= x >> 16;
+	x ^= x >> 8;
+	x ^= x >> 4;
+	return BIT(0x6996, x & 0xf);
+#else
+        __asm(    "movl %1, %%eax\n"
+		"mov %%ax, %%cx\n"
+		"shrl $0x10, %%eax\n"
+		"xor %%ax, %%cx\n"
+                "xor %%ch, %%cl\n"
+                "setpo %%al\n"
+                "movzx %%al, %0\n": "=r"(x) : "r"(x): "eax","ecx");
+	return x;
+#endif
+}
+static inline int filter(uint32_t const x)
+{
+	uint32_t f;
+
+	f  = 0xf22c0 >> (x       & 0xf) & 16;
+	f |= 0x6c9c0 >> (x >>  4 & 0xf) &  8;
+	f |= 0x3c8b0 >> (x >>  8 & 0xf) &  4;
+	f |= 0x1e458 >> (x >> 12 & 0xf) &  2;
+	f |= 0x0d938 >> (x >> 16 & 0xf) &  1;
+	return BIT(0xEC57E80A, f);
+}
+#ifdef __cplusplus
+}
+#endif
+#endif
diff --git a/common/crapto1/crypto1.c b/common/crapto1/crypto1.c
new file mode 100644
index 00000000..f3bb0d73
--- /dev/null
+++ b/common/crapto1/crypto1.c
@@ -0,0 +1,113 @@
+/*  crypto1.c
+
+	This program is free software; you can redistribute it and/or
+	modify it under the terms of the GNU General Public License
+	as published by the Free Software Foundation; either version 2
+	of the License, or (at your option) any later version.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program; if not, write to the Free Software
+	Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+	MA  02110-1301, US
+
+	Copyright (C) 2008-2008 bla <blapost@gmail.com>
+*/
+#include "crapto1.h"
+#include <stdlib.h>
+
+#define SWAPENDIAN(x)\
+	(x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16)
+
+#if defined(__arm__)
+void crypto1_create(struct Crypto1State *s, uint64_t key)
+{
+#else
+struct Crypto1State * crypto1_create(uint64_t key)
+{
+	struct Crypto1State *s = malloc(sizeof(*s));
+#endif
+	int i;
+
+	for(i = 47;s && i > 0; i -= 2) {
+		s->odd  = s->odd  << 1 | BIT(key, (i - 1) ^ 7);
+		s->even = s->even << 1 | BIT(key, i ^ 7);
+	}
+#if defined(__arm__)	
+	return;
+#else
+	return s;
+#endif
+}
+#if defined(__arm__)
+void crypto1_destroy(struct Crypto1State *state)
+{
+	state->odd = 0;
+	state->even = 0;
+}
+#else
+void crypto1_destroy(struct Crypto1State *state)
+{
+	free(state);
+}
+#endif
+void crypto1_get_lfsr(struct Crypto1State *state, uint64_t *lfsr)
+{
+	int i;
+	for(*lfsr = 0, i = 23; i >= 0; --i) {
+		*lfsr = *lfsr << 1 | BIT(state->odd, i ^ 3);
+		*lfsr = *lfsr << 1 | BIT(state->even, i ^ 3);
+	}
+}
+uint8_t crypto1_bit(struct Crypto1State *s, uint8_t in, int is_encrypted)
+{
+	uint32_t feedin;
+	uint32_t tmp;
+	uint8_t ret = filter(s->odd);
+
+	feedin  = ret & !!is_encrypted;
+	feedin ^= !!in;
+	feedin ^= LF_POLY_ODD & s->odd;
+	feedin ^= LF_POLY_EVEN & s->even;
+	s->even = s->even << 1 | parity(feedin);
+
+	tmp = s->odd;
+	s->odd = s->even;
+	s->even = tmp;
+
+	return ret;
+}
+uint8_t crypto1_byte(struct Crypto1State *s, uint8_t in, int is_encrypted)
+{
+	uint8_t i, ret = 0;
+
+	for (i = 0; i < 8; ++i)
+		ret |= crypto1_bit(s, BIT(in, i), is_encrypted) << i;
+
+	return ret;
+}
+uint32_t crypto1_word(struct Crypto1State *s, uint32_t in, int is_encrypted)
+{
+	uint32_t i, ret = 0;
+
+	for (i = 0; i < 4; ++i, in <<= 8)
+		ret = ret << 8 | crypto1_byte(s, in >> 24, is_encrypted);
+
+	return ret;
+}
+
+/* prng_successor
+ * helper used to obscure the keystream during authentication
+ */
+uint32_t prng_successor(uint32_t x, uint32_t n)
+{
+	SWAPENDIAN(x);
+	while(n--)
+		x = x >> 1 | (x >> 16 ^ x >> 18 ^ x >> 19 ^ x >> 21) << 31;
+
+	return SWAPENDIAN(x);
+}
diff --git a/tools/mfkey/mfkey32.h b/tools/mfkey/mfkey32.h
new file mode 100644
index 00000000..7fb4014b
--- /dev/null
+++ b/tools/mfkey/mfkey32.h
@@ -0,0 +1,22 @@
+#ifndef __MFKEY32_H
+#define __MFKEY32_H
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+typedef struct {
+	uint32_t cuid;
+	uint8_t  sector;
+	uint8_t  keytype;
+	uint32_t nonce;
+	uint32_t ar;
+	uint32_t nr;
+	uint32_t nonce2;
+	uint32_t ar2;
+	uint32_t nr2;
+} nonces_t;
+
+bool mfkey32(nonces_t data, uint64_t *outputkey);
+bool tryMfk32_moebius(nonces_t data, uint64_t *outputkey);
+
+#endif
\ No newline at end of file
diff --git a/tools/nonce2key/readme.txt b/tools/nonce2key/readme.txt
new file mode 100644
index 00000000..315f5a87
--- /dev/null
+++ b/tools/nonce2key/readme.txt
@@ -0,0 +1,13 @@
+To test the nonce2key tool.
+
+:: tip
+You can use the output from "hf mf mifare"  to use with this tool. 
+
+:: sample
+./nonce2key 1b2a28f5 73a4c24c 00000000 734b3b93eb4bd303 0d0d060f0f0f0200
+
+If all parity bits are 0, it is assumed that this is a Mifare clone responding with NACK to all wrong authentication attempts.
+In this case, a special attack is used (which usually results in many possible keys)
+
+:: sample with all parity bits 0:
+./nonce2key 2e086b1a 2210af4e 00000002 0000000000000000 050708040a030b06