Updating modexp core to v 0.50. This version contains a working core that can perform sign and verify with big keys/values. The core builds ok in Altera and Xilinx FPGA tools. This commit also includes a new testgenerator capable of generating testbench for modexp with autgenerated test data of different lengths. The README has been updated with status and implementation results in for different FPGA devices.

3 files changed, 163 insertions, 16 deletions

diff --git a/src/model/c/src/autogenerated_tests.c b/src/model/c/src/autogenerated_tests.c
index e9ec0b7..2a80c42 100644
--- a/src/model/c/src/autogenerated_tests.c
+++ b/src/model/c/src/autogenerated_tests.c
@@ -202,6 +202,146 @@ void autogenerated_BASIC_M7037130911981370263(void) {
   mod_exp_array(1, X, E, M, Z);
   assertArrayEquals(1, expected, Z);
 }
+void autogenerated_BASIC_5073338267670769216(void) {
+  printf("=== autogenerated_BASIC_5073338267670769216 ===\n");
+  uint32_t X[] = { 0x3028983f, 0xdc9bdc25, 0xa3fdfeda, 0x283f4463 };
+  uint32_t E[] = { 0x29493211, 0xc4252db0, 0x7775443d, 0x13e1d929 };
+  uint32_t M[] = { 0x2fb9ba2f, 0xa485d5f7, 0x3c6652c9, 0x670fdbfd };
+  uint32_t expected[] = { 0x2f45cdd6, 0x23f0e6f2, 0xaa4bd5d8, 0x6297da06 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_M1841989679506188752(void) {
+  printf("=== autogenerated_BASIC_M1841989679506188752 ===\n");
+  uint32_t X[] = { 0x29462882, 0x12caa2d5, 0xb80e1c66, 0x1006807f };
+  uint32_t E[] = { 0x3285c343, 0x2acbcb0f, 0x4d023228, 0x2ecc73db };
+  uint32_t M[] = { 0x267d2f2e, 0x51c216a7, 0xda752ead, 0x48d22d89 };
+  uint32_t expected[] = { 0x0ddc404d, 0x91600596, 0x7425a8d8, 0xa066ca56 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_M3339729654500648482(void) {
+  printf("=== autogenerated_BASIC_M3339729654500648482 ===\n");
+  uint32_t X[] = { 0x2963efb9, 0xc6f5d260, 0xa2d0fe74, 0x49726b57 };
+  uint32_t E[] = { 0x2f55c103, 0xbace4bf1, 0x2ab9fac2, 0x30aec7d3 };
+  uint32_t M[] = { 0x376cf9ae, 0xd9e988e8, 0xbd995f5c, 0xdeec42f5 };
+  uint32_t expected[] = { 0x0ce8cff7, 0x9f564e2c, 0x1b61e3d9, 0x717db9ef };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_M6837928193394880512(void) {
+  printf("=== autogenerated_BASIC_M6837928193394880512 ===\n");
+  uint32_t X[] = { 0x2a9283cc, 0x5999f49d, 0xf8cf6ab2, 0x5f47bf25 };
+  uint32_t E[] = { 0x2c7564a0, 0x2d1fcda1, 0x2825318a, 0xae23c271 };
+  uint32_t M[] = { 0x32b892f9, 0x096c5ada, 0x43918370, 0x8398c7e3 };
+  uint32_t expected[] = { 0x27cf8839, 0x94004d82, 0xa0d69d86, 0x3f61a929 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_M7333111649825079555(void) {
+  printf("=== autogenerated_BASIC_M7333111649825079555 ===\n");
+  uint32_t X[] = { 0x246fa2ec, 0x405f234d, 0x39b93e77, 0xf16bcc91 };
+  uint32_t E[] = { 0x2807eb7a, 0x646df633, 0xeaa95a21, 0x85252adf };
+  uint32_t M[] = { 0x2cdd3307, 0x782e5711, 0x584f179b, 0x011087df };
+  uint32_t expected[] = { 0x02d6e42e, 0x46e2d304, 0x435170c1, 0x9f344f83 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_480186175131589607(void) {
+  printf("=== autogenerated_BASIC_480186175131589607 ===\n");
+  uint32_t X[] = { 0x300a5cf7, 0x269f6369, 0x02e025cb, 0xaf16fcfd };
+  uint32_t E[] = { 0x2cc4b1c0, 0x9205a8b4, 0xbc130ee2, 0x923f1f3f };
+  uint32_t M[] = { 0x2cd376d5, 0xd9e3b080, 0x2533288a, 0xd4b9bb37 };
+  uint32_t expected[] = { 0x0ae9c475, 0xf4fb4c63, 0xcf2c4f56, 0x902eba0c };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_M5239159917778665002(void) {
+  printf("=== autogenerated_BASIC_M5239159917778665002 ===\n");
+  uint32_t X[] = { 0x3eaed5af, 0xa287db7e, 0x4ff07fee, 0x9bbda80b };
+  uint32_t E[] = { 0x3c077d49, 0xf3a131ab, 0x6289042a, 0xc15083cb };
+  uint32_t M[] = { 0x344b8538, 0xcf4f2576, 0xd28c1c52, 0xc83a8199 };
+  uint32_t expected[] = { 0x15028046, 0x5c12d235, 0x7580fd1b, 0x6bc76b24 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_228752064885223799(void) {
+  printf("=== autogenerated_BASIC_228752064885223799 ===\n");
+  uint32_t X[] = { 0x3904d7ab, 0x13937a4f, 0x926856d1, 0x6bdda621 };
+  uint32_t E[] = { 0x3d360083, 0xa50eaf0e, 0xffce2df2, 0xb1f51cef };
+  uint32_t M[] = { 0x2d32376f, 0x205555b3, 0x2c9daf8c, 0xe2b7cf81 };
+  uint32_t expected[] = { 0x08836692, 0xe6398828, 0x1eeccd57, 0x2c231153 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_856940511857911599(void) {
+  printf("=== autogenerated_BASIC_856940511857911599 ===\n");
+  uint32_t X[] = { 0x23e80223, 0x52b700ee, 0x6cb8a294, 0x47c6fac9 };
+  uint32_t E[] = { 0x253cebdb, 0xcc78dcb4, 0x925682b3, 0x490c424b };
+  uint32_t M[] = { 0x2f2885eb, 0x67987cee, 0x717298bd, 0x7a1baf7b };
+  uint32_t expected[] = { 0x2bb0b86c, 0xc854652b, 0x2b2bce27, 0xd2595a8e };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_M6501553661140603953(void) {
+  printf("=== autogenerated_BASIC_M6501553661140603953 ===\n");
+  uint32_t X[] = { 0x287e9711, 0x4d346dab, 0x3ff5e6da, 0xa93edebd };
+  uint32_t E[] = { 0x3658192a, 0x4b5fac3f, 0x9a78bc81, 0x5ac8c667 };
+  uint32_t M[] = { 0x238cd95d, 0x298ee5e1, 0x320323da, 0x0a46ec21 };
+  uint32_t expected[] = { 0x0415fef6, 0x5fc81702, 0x8be83fd4, 0x4c7fbf24 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(4, X, E, M, Z);
+  assertArrayEquals(4, expected, Z);
+}
+void autogenerated_BASIC_M8496483018338900149(void) {
+  printf("=== autogenerated_BASIC_M8496483018338900149 ===\n");
+  uint32_t X[] = { 0x3b4511d5, 0x5f61da31, 0x4bf252e0, 0x3962f93c, 0x590171d0, 0xda31097f, 0x0f73fee3, 0x0ba1b379, 0x514b7d8f, 0x1e337cf9, 0x733512ac, 0x4f5b0b52, 0x40762697, 0xb3a30c84, 0x5563b4db, 0x59f7cef1 };
+  uint32_t E[] = { 0x271cb7c4, 0x11f07a63, 0x1df850e7, 0x8bf6df66, 0x7bc8fa0e, 0xa51002ce, 0xf16946c5, 0x96916dc7, 0xba1681b1, 0x5ca395ab, 0x7839780d, 0xc5e760c3, 0x578af4f9, 0xffbbbd8c, 0x8576c8fc, 0x518012a7 };
+  uint32_t M[] = { 0x3c0f154d, 0x7fc7750a, 0x03eb8968, 0xfbde501a, 0x63848fe5, 0xdcd7d883, 0x5131c9f9, 0xa9ca3399, 0xba581205, 0x4cf86f2a, 0xed928b92, 0x13a0e90f, 0x5b24c81a, 0xf4ac077c, 0x68b8ac70, 0xc58961fd };
+  uint32_t expected[] = { 0x30d0a0c1, 0x1be7b00f, 0x9ed921c6, 0x7a7f9a87, 0xb8ed7f88, 0xd81f20d5, 0xb3ba9839, 0x38dfdfb4, 0x70b1927c, 0xa4b9487b, 0x8d8d7e2c, 0xc706e737, 0x17e9c280, 0xbec0006a, 0xeea7dc97, 0x4f5badc9 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(16, X, E, M, Z);
+  assertArrayEquals(16, expected, Z);
+}
+void autogenerated_BASIC_6145567102166328515(void) {
+  printf("=== autogenerated_BASIC_6145567102166328515 ===\n");
+  uint32_t X[] = { 0x23446522, 0x9185c81e, 0x09283a50, 0x82c1f517, 0xd00d3159, 0x846c2c99, 0x261d1dcb, 0xde183d66, 0x98f8a990, 0xd295bd50, 0x09ef8644, 0xadcf9cdb, 0x5eec13a3, 0x92baa627, 0x18caa215, 0x8836480f };
+  uint32_t E[] = { 0x397f2b38, 0xa95cc0bc, 0xc13b26cf, 0xa20dda3c, 0xf8801c39, 0x00731abe, 0x2ad0afc4, 0xdb247141, 0xc29b5a2d, 0x9e51a3ed, 0xcf364a51, 0x90b761d5, 0xfa0624d3, 0x3a0b27c7, 0xa36bc66c, 0x6423efd3 };
+  uint32_t M[] = { 0x3ad2464f, 0x75da362c, 0x6e5c37b4, 0x432cc6b7, 0x6f48b57c, 0xebb87e14, 0x0a3d3f4d, 0xfa4c32c0, 0x165a5892, 0x742f720d, 0x8b4e1b43, 0x281d5390, 0xff2f77dc, 0x698dbc05, 0xdee97a68, 0xde2c176d };
+  uint32_t expected[] = { 0x083aa822, 0x7c70341a, 0xa2cbc9a8, 0xd116bc41, 0x79a81ba7, 0x584c91c8, 0x5b87c314, 0xc5e6f4f9, 0x601ebead, 0x054bf14b, 0x65b48a4a, 0xf8aa2700, 0xa765ee1d, 0xb6c638cd, 0x7e529f23, 0x0d4adfff };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(16, X, E, M, Z);
+  assertArrayEquals(16, expected, Z);
+}
+void autogenerated_BASIC_7216348574014690328(void) {
+  printf("=== autogenerated_BASIC_7216348574014690328 ===\n");
+  uint32_t X[] = { 0x35baa860, 0x4e47ad49, 0xc6c4a7c0, 0x7857335b, 0x9b81d24f, 0x7be86e34, 0xf84f7560, 0x484b20db, 0xb83b4f9e, 0x694c6987, 0x7d3232f5, 0x18ee8603, 0x94eca5ef, 0x5179ef69, 0xf6600efb, 0xfc71deab, 0xdb939552, 0x642db1e0, 0x78e11e39, 0x924f0dbd, 0xdb225803, 0x449bbb35, 0xfc40ee05, 0x9b19931c, 0x8b8af884, 0xb5f96476, 0xf97ad419, 0xcc7543f9, 0xce25ed83, 0x94da3499, 0x4f37f331, 0xe64e7799 };
+  uint32_t E[] = { 0x3a7570f2, 0x38cb0f2f, 0x2e6c8989, 0xcf7c2665, 0xa0fce3d0, 0x12c7a8eb, 0x40fab1ea, 0x39eb4809, 0x822fa6cc, 0x4ef9d604, 0x2ca1cd3b, 0xa9b23cdb, 0x17e823ce, 0x5fea5198, 0x1ab12946, 0xcec748b5, 0x752a3a6f, 0x73421a9a, 0x7138d7a4, 0xa47327c0, 0x17475543, 0xe841c19a, 0x3085410a, 0x06438b4c, 0xe0d4b918, 0xfeccca17, 0x9ed86072, 0x86db4a93, 0x60c7d437, 0xcdfe77e3, 0x2631f264, 0x80c9b645 };
+  uint32_t M[] = { 0x34d90901, 0xf192009c, 0xc34f345f, 0x63f592b2, 0xaba32d7a, 0x161d1510, 0x2c264dec, 0x07306f1d, 0x3e61c031, 0xacd4eba0, 0xff1318ff, 0x09a78cf4, 0x97bace67, 0xc8fcecf4, 0x3b3901a3, 0x5d447957, 0xc0397708, 0x7e7e48f9, 0x571db58a, 0x80d65921, 0x68a025e0, 0x4f85f776, 0xaa8450c7, 0x15c42f52, 0xe65507f2, 0xdfeed660, 0x0db8eddb, 0xb1e48d93, 0x7e314a2f, 0xea81ccb1, 0xbe22cc03, 0xf2928621 };
+  uint32_t expected[] = { 0x14c07087, 0x3e92a437, 0xbfd5a5b3, 0xec017ed5, 0xacf23e12, 0x6e48a51f, 0xe1fdbde9, 0x43fade6b, 0x98935c7a, 0xaff9b1e5, 0x3adaa120, 0xcbaa5af5, 0x344fabb2, 0x8d2987c7, 0xfb83d342, 0x3f85bbfc, 0xc30e755a, 0x37f20fa4, 0x7fb5621b, 0xcd1cef03, 0x664ccb56, 0xce0a28b9, 0xa9cbdd51, 0xad12eb24, 0xacc08c8d, 0x5d9fe7f5, 0x018c1e1e, 0x2115bba8, 0x22b52262, 0xaee3bf8a, 0x91824a22, 0xde48a1f3 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(32, X, E, M, Z);
+  assertArrayEquals(32, expected, Z);
+}
+void autogenerated_BASIC_M5663191947183200100(void) {
+  printf("=== autogenerated_BASIC_M5663191947183200100 ===\n");
+  uint32_t X[] = { 0x21558179, 0x3e2914b1, 0xefe95957, 0x965fdead, 0xe766d8fc, 0x136eadf4, 0xa6106a2a, 0x88b2df7e, 0xe0b0eaae, 0x2c17946a, 0x6f5b5563, 0x228052ae, 0x7fc40d80, 0xf81354db, 0xfceecd1a, 0xa5e4c97d, 0x433ecfcd, 0xc20d1e4d, 0x2a748fe3, 0x1d9e63f0, 0xdc6c25d6, 0xdae5c8be, 0x1d8c5431, 0xb1d7d270, 0xed5b2566, 0x1463b0fd, 0xa9e26cf7, 0x3dd6fbd7, 0x1347c8f7, 0x76c2cc37, 0xf382b786, 0x1d5ac517, 0x26b96692, 0x2c1fe6f8, 0x5852dbf8, 0x4bcabda2, 0xbedb2f5f, 0xbfe58158, 0x8cd5d15f, 0xac7c7f4c, 0xf8ba47d2, 0x86c6571d, 0x06a4760b, 0xa6afa0e1, 0x7a819f62, 0x5cdbfe15, 0x9b2d10b5, 0xf508b1fd, 0xb3f0462a, 0x92f45a64, 0x69b6ec58, 0xbfad8fab, 0x6799260f, 0x27415db5, 0xf6ac7832, 0xe547826d, 0x6a9806a5, 0x36c62a88, 0x98bee14d, 0x9b8c2648, 0xabdbbd3d, 0xaf59eea1, 0x164eacb5, 0x3a18e427 };
+  uint32_t E[] = { 0x2519837b, 0xe73a9031, 0xe241606d, 0x21e70fa2, 0x7881f254, 0x4e60831d, 0x266f408e, 0x4a83e6ed, 0xa7741995, 0x32b477ba, 0x91bdf5d0, 0x4acd7a06, 0x51e344b9, 0xdf376e4e, 0x8494e625, 0xa0cc9697, 0x817a0c93, 0x3b68cefb, 0x46de14c1, 0x52229965, 0x329645bd, 0xf4176adc, 0x29a8bc50, 0x44900fec, 0x1558d492, 0xf838a8e7, 0xea207abd, 0xcd21a28c, 0x91e6b02f, 0x2a490ea8, 0x5d99663b, 0x87c92fb6, 0x0a185325, 0x5256a7a3, 0x496b7288, 0x6688b6c8, 0x650e1776, 0x54cd429f, 0x90ea3b18, 0x0b72ae61, 0xcc8651b3, 0xa488742d, 0x93c401ef, 0x5a2220ff, 0xaee1f257, 0xf9d1e29a, 0xd47151fe, 0x4978342b, 0x0927048a, 0x404b0689, 0xdc9df8cc, 0xfba9845f, 0xeb8a39b0, 0xd3f24ae2, 0x5ea9ca0a, 0x0c064f94, 0x35368ae2, 0xeab6c035, 0x9baa39c6, 0x2ef6259d, 0xa2577555, 0x514c7d98, 0x0890d44f, 0xf416fbdd };
+  uint32_t M[] = { 0x2c5337a9, 0x3f2e1ca6, 0x91de65ea, 0xc3f9a3c2, 0xdc9099e0, 0x64ebe412, 0xf4583fae, 0x1fc8e8dd, 0x92dcbbfb, 0x9159239e, 0xdbbec456, 0x8735a660, 0x8248dbbc, 0x76f01415, 0x3cb8a897, 0x7cc09280, 0x6cc6db51, 0x9c2544da, 0x316564ce, 0x4b6d9b3b, 0x3e0e123f, 0x942a4a3c, 0x1f128873, 0x5ad14862, 0xdde8e6dd, 0x73da31fb, 0x1a8a2046, 0xc3ff18c6, 0x24e31d54, 0x7d8a1796, 0x88ab346c, 0x262bb321, 0x2cada5dc, 0x1fb2284c, 0x042375fd, 0xba10d309, 0xcda978ec, 0x229ee156, 0x8470728a, 0xa58017fd, 0x65727801, 0x1ea396a6, 0xbd9a4bc1, 0x8e97c08f, 0xd7529796, 0x2c8339e9, 0xc5340a83, 0x6f7d1f9c, 0xd6014fec, 0xdffa2265, 0xfa9906a9, 0xafbd424a, 0x631994ae, 0x73a9b3f1, 0x2284f999, 0x6f8c87f6, 0x93136a66, 0x47c81e45, 0xd35f0e41, 0x238d6960, 0x96cf337d, 0x8865e4cc, 0x15039c40, 0x65ee7211 };
+  uint32_t expected[] = { 0x24665860, 0x4b150493, 0xc0834602, 0xc0b99ab5, 0xbe649545, 0xa7d8b1ca, 0x55c1b98a, 0x1dce374b, 0x65750415, 0x573dfed7, 0x95df9943, 0x58a4aea0, 0x5fb40a92, 0x1408d9c2, 0xb5e23fc9, 0x225eb60b, 0x41d33a41, 0xbf958f7f, 0x619f5ac1, 0x207647f3, 0x223e56f8, 0x26afd4ae, 0x6a297840, 0x830947db, 0xbc5af940, 0x4c97ebb1, 0xca38b220, 0x04c9a26d, 0x49a16b72, 0x0882c658, 0x2dbc50e0, 0x67e2d057, 0x4b8ef356, 0x4ba5eac3, 0x17237d9f, 0x27c111a8, 0xc1b1944e, 0xe91fd6b6, 0xa78d9747, 0x61e946d3, 0x0078fe23, 0x7770a088, 0x6d5762af, 0x435ac5f9, 0x36cde9d5, 0xc313804d, 0xa4623760, 0xb1c37572, 0x2b22486d, 0x8af131e3, 0x3e5fc3ea, 0x0d9c9ba0, 0x218bcc8f, 0x8bcdfea2, 0xcf55a599, 0x57b9fcbc, 0x5c087f62, 0xec130a15, 0x7e8bd1f5, 0x60eaaa51, 0x020dd89b, 0x890cc6ea, 0x042d0054, 0x74055863 };
+  uint32_t Z[] = { 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000, 0x00000000 };
+  mod_exp_array(64, X, E, M, Z);
+  assertArrayEquals(64, expected, Z);
+}
 void autogenerated_tests(void) {
   autogenerated_BASIC_M4962768465676381896();
   autogenerated_BASIC_8982867242010371843();
@@ -223,5 +363,19 @@ void autogenerated_tests(void) {
   autogenerated_BASIC_M2453278165832221565();
   autogenerated_BASIC_M1847183855567461116();
   autogenerated_BASIC_M7037130911981370263();
+  autogenerated_BASIC_5073338267670769216();
+  autogenerated_BASIC_M1841989679506188752();
+  autogenerated_BASIC_M3339729654500648482();
+  autogenerated_BASIC_M6837928193394880512();
+  autogenerated_BASIC_M7333111649825079555();
+  autogenerated_BASIC_480186175131589607();
+  autogenerated_BASIC_M5239159917778665002();
+  autogenerated_BASIC_228752064885223799();
+  autogenerated_BASIC_856940511857911599();
+  autogenerated_BASIC_M6501553661140603953();
+  autogenerated_BASIC_M8496483018338900149();
+  autogenerated_BASIC_6145567102166328515();
+  autogenerated_BASIC_7216348574014690328();
+  autogenerated_BASIC_M5663191947183200100();
 
 }
diff --git a/src/model/c/src/montgomery_array.c b/src/model/c/src/montgomery_array.c
index 0ddc742..c3579a9 100644
--- a/src/model/c/src/montgomery_array.c
+++ b/src/model/c/src/montgomery_array.c
@@ -3,22 +3,15 @@
 #include "bignum_uint32_t.h"
 #include "montgomery_array.h"
 
-void mont_prod_array(uint32_t length, uint32_t *A, uint32_t *B, uint32_t *M,
-		uint32_t *temp, uint32_t *s) {
+void mont_prod_array(uint32_t length, uint32_t *A, uint32_t *B, uint32_t *M, uint32_t *s) {
 	zero_array(length, s);
 	for (int32_t wordIndex = ((int32_t) length) - 1; wordIndex >= 0; wordIndex--) {
 		for (int i = 0; i < 32; i++) {
 
-			int b = (B[wordIndex] >> i) & 1;
+			uint32_t b = (B[wordIndex] >> i) & 1;
 
 			//q = (s - b * A) & 1;
-			sub_array(length, s, A, temp);
-			int q;
-			if (b == 1) {
-				q = temp[length - 1] & 1;
-			} else {
-				q = s[length - 1] & 1;
-			}
+			uint32_t q = (s[length-1] ^ (A[length-1] & b)) & 1; // int q = (s - b * A) & 1;
 
 			// s = (s + q*M + b*A) >>> 1;
 			if (q == 1) {
@@ -77,11 +70,11 @@ void mont_exp_array(uint32_t length, uint32_t *X, uint32_t *E, uint32_t *M,
 	// 2. Z0 := MontProd( 1, Nr, M )
 	zero_array(length, ONE);
 	ONE[length - 1] = 1;
-	mont_prod_array(length, ONE, Nr, M, temp, Z);
+	mont_prod_array(length, ONE, Nr, M, Z);
 	//debugArray("Z0", length, Z);
 
 	// 3. P0 := MontProd( X, Nr, M );
-	mont_prod_array(length, X, Nr, M, temp, P);
+	mont_prod_array(length, X, Nr, M, P);
 	//debugArray("P0", length, P);
 
 	// 4. for i = 0 to n-1 loop
@@ -91,18 +84,18 @@ void mont_exp_array(uint32_t length, uint32_t *X, uint32_t *E, uint32_t *M,
 		uint32_t ei = (ei_ >> (i % 32)) & 1;
 		// 6. if (ei = 1) then Zi+1 := MontProd ( Zi, Pi, M) else Zi+1 := Zi
 		if (ei == 1) {
-			mont_prod_array(length, Z, P, M, temp, temp2);
+			mont_prod_array(length, Z, P, M, temp2);
 			copy_array(length, temp2, Z);
 			//debugArray("Z ", length, Z);
 		}
 		// 5. Pi+1 := MontProd( Pi, Pi, M );
-		mont_prod_array(length, P, P, M, temp, temp2);
+		mont_prod_array(length, P, P, M, temp2);
 		copy_array(length, temp2, P);
 		//debugArray("P ", length, P);
 		// 7. end for
 	}
 	// 8. Zn := MontProd( 1, Zn, M );
-	mont_prod_array(length, ONE, Z, M, temp, temp2);
+	mont_prod_array(length, ONE, Z, M, temp2);
 	copy_array(length, temp2, Z);
 	//debugArray("Z ", length, Z);
 	// 9. RETURN Zn
diff --git a/src/model/c/src/montgomery_array.h b/src/model/c/src/montgomery_array.h
index 82ef9de..984bc07 100644
--- a/src/model/c/src/montgomery_array.h
+++ b/src/model/c/src/montgomery_array.h
@@ -9,7 +9,7 @@
 #define MONTGOMERY_ARRAY_H_
 
 void mont_prod_array(uint32_t length, uint32_t *A, uint32_t *B, uint32_t *M,
-		uint32_t *temp, uint32_t *s);
+		uint32_t *s);
 void mod_exp_array(uint32_t length, uint32_t *X, uint32_t *E, uint32_t *M, uint32_t *Z);
 
 #endif /* MONTGOMERY_ARRAY_H_ */