Home‎ > ‎GC1P8QN‎ > ‎

### Factorizing with msieve.exe

 Here'a a quite good factorization tool msieve.exe. The following instructions are for a DOS shell user. Window&rodent entusiastics sure know how to do it in a more modern way. Usage 1) Execute msieve.exe (The name can also be "msieve142.exe" or something similar.)  with the number as argument. 2) A file msieve.log will be created in the same directory you did execute the msieve.exe. This log file will contain the solved prime factors of the given number. Example 1: c:\tmp>msieve 35 c:\tmp>type msieve.log Sun Jun 07 11:14:03 2009Sun Jun 07 11:14:03 2009Sun Jun 07 11:14:03 2009  Msieve v. 1.41Sun Jun 07 11:14:03 2009  random seeds: 6b621e54 f478feeeSun Jun 07 11:14:03 2009  factoring 35 (2 digits)Sun Jun 07 11:14:03 2009  p1 factor: 5Sun Jun 07 11:14:03 2009  p1 factor: 7Sun Jun 07 11:14:03 2009  elapsed time 00:00:00c:\tmp> Thus the prime factors of 35 are 5 and 7. In other words 35 = 5 x 7 Example 2 (This is the performance test example): c:\tmp>msieve 5382000000735683358022919837657883000000078236999000000000000063 c:\tmp>type msieve.log Sun Jun 07 11:46:55 2009 Sun Jun 07 11:46:55 2009 Sun Jun 07 11:46:55 2009  Msieve v. 1.41 Sun Jun 07 11:46:55 2009  random seeds: 70e08de8 ba685f00 Sun Jun 07 11:46:55 2009  factoring 53820000007356833580229198376578830000000782 36999000000000000063 (64 digits) Sun Jun 07 11:46:55 2009  searching for 15-digit factors Sun Jun 07 11:46:57 2009  commencing quadratic sieve (64-digit input) Sun Jun 07 11:46:57 2009  using multiplier of 3 Sun Jun 07 11:46:57 2009  using 32kb Intel Core sieve core Sun Jun 07 11:46:57 2009  sieve interval: 12 blocks of size 32768 Sun Jun 07 11:46:57 2009  processing polynomials in batches of 17 Sun Jun 07 11:46:57 2009  using a sieve bound of 114001 (5400 primes) Sun Jun 07 11:46:57 2009  using large prime bound of 5700050 (22 bits) Sun Jun 07 11:46:57 2009  using trial factoring cutoff of 22 bits Sun Jun 07 11:46:57 2009  polynomial 'A' values have 8 factors Sun Jun 07 11:47:21 2009  6053 relations (2763 full + 3290 combined from 26081 partial), need 5496 Sun Jun 07 11:47:21 2009  begin with 28844 relations Sun Jun 07 11:47:21 2009  reduce to 8877 relations in 2 passes Sun Jun 07 11:47:21 2009  attempting to read 8877 relations Sun Jun 07 11:47:21 2009  recovered 8877 relations Sun Jun 07 11:47:21 2009  recovered 6828 polynomials Sun Jun 07 11:47:21 2009  attempting to build 6053 cycles Sun Jun 07 11:47:21 2009  found 6053 cycles in 1 passes Sun Jun 07 11:47:21 2009  distribution of cycle lengths: Sun Jun 07 11:47:21 2009     length 1 : 2763 Sun Jun 07 11:47:21 2009     length 2 : 3290 Sun Jun 07 11:47:21 2009  largest cycle: 2 relations Sun Jun 07 11:47:21 2009  matrix is 5400 x 6053 (0.7 MB) with weight 165072 (27.27/col) Sun Jun 07 11:47:21 2009  sparse part has weight 165072 (27.27/col) Sun Jun 07 11:47:21 2009  filtering completed in 4 passes Sun Jun 07 11:47:21 2009  matrix is 4999 x 5063 (0.6 MB) with weight 131741 (26.02/col) Sun Jun 07 11:47:21 2009  sparse part has weight 131741 (26.02/col) Sun Jun 07 11:47:21 2009  commencing Lanczos iteration Sun Jun 07 11:47:21 2009  memory use: 0.8 MB Sun Jun 07 11:47:22 2009  lanczos halted after 81 iterations (dim = 4997) Sun Jun 07 11:47:22 2009  recovered 64 nontrivial dependencies Sun Jun 07 11:47:22 2009  prp32 factor: 69000000003314259000000000000007 Sun Jun 07 11:47:22 2009  prp32 factor: 78000000006915524000000000000009 Sun Jun 07 11:47:22 2009  elapsed time 00:00:27c:\tmp> The prime factors of 5382000000735683358022919837657883000000078236999000000000000063 are thus 69000000003314259000000000000007 and 78000000006915524000000000000009. In other words 5382000000735683358022919837657883000000078236999000000000000063 = 69000000003314259000000000000007 x 78000000006915524000000000000009. (By the way, ASCII code for E is 69 and ASCII code for N is 78.) The elapsed time, 27 seconds, is a result of a desktop PC with Intel 2 GHz CPU running some other applications at the same time. You can give the argument also by creating a file worktodo.ini containing one line N= where is the number to be factorized. For example N=35 or N=5382000000735683358022919837657883000000078236999000000000000063 or the ultimate N=53830765614815296147077056056897689769993289313646389390585730478414476891677078524821470774994245604550003267[Edited 2009-09-28. New link to msieve142.exe]