Resume linear algebra

[VictordeHolland]

Let's hope that the person is sane and doesn't do anything illegal with the factorization of a RSA-512 bit number

[Timic]

Haha, nothing illegal, don't worry.

[VBCurtis]

Try the -nc version of the command. Filtering (the -nc1 step that happens between sieving and solving the matrix) is somewhat memory-sensitive, and may have given you a matrix that doesn't solve. So, erase the .cyc file, and run the command line you have but with -nc at the end rather than -nc2.

It will proceed to read all the relations, build a matrix, solve the matrix, and run the final step (square root). Those are individually -nc1, -nc2, and -nc3; runnning -nc does all 3 in order.

Good luck!

[EdH]

This is kind of what VBCurtis has said, but I would add, start with "only" the rsa.dat, rsa.fb and whichever (rsa.n or rsa.ini) has the composite in it. These three files should be all you need. I would also run all three steps separate, although as VBCurtis mentioned -nc would do all three in order and the log file would allow you to observe the activity.

To recap (three files only):

msieve -i rsa.n (or rsa.ini) -s rsa.dat -l rsa.log -nf rsa.fb -nc1

msieve -i rsa.n (or rsa.ini) -s rsa.dat -l rsa.log -nf rsa.fb -nc2

msieve -i rsa.n (or rsa.ini) -s rsa.dat -l rsa.log -nf rsa.fb -nc3

or

msieve -i rsa.n (or rsa.ini) -s rsa.dat -l rsa.log -nf rsa.fb -nc

[Timic]

I tried what VBCurtis said and it threw same errors after building matrix and stuff.

lanczos halted after 9 iterations (dim = 510)
linear algebra failed; retrying...
commencing Lanczos iteration (4 threads)
memory use: 867.6 MB
lanczos error: submatrix is not invertible

Trying EdH's now (I also included the .poly or should I remove that too?)... but I doubt it will work.

It could be the binaries? I got them from here. I'm using gnfs-win64-ivybridge-asm64 and msieve152_svn939_win64_i7. Do I have to compile from source? Using Windows 10 on the new machine by the way.

[VictordeHolland]

Originally Posted by Timic

It could be the binaries? I got them from here. I'm using gnfs-win64-ivybridge-asm64 and msieve152_svn939_win64_i7. Do I have to compile from source? Using Windows 10 on the new machine by the way.

What machine did you do the sieving on? the name of the binary implies it is compiled for windows x64 Ivybridge (probably will work on later architectures)?

Same for the machine you're running Msieve on, is it win64 i7 (or later)?

If you're sure you're using the correct binaries, and still can't get past the linear algebra, maybe you could send your relations (.dat)(preferably compressed like .gz or .7z or .zip etc.) and poly (.fb .poly) to somebody on the forum to eliminate the machine/setup not working correctly. You might have to split it so you can upload/send it (for instance wetransfer.com has a 2GB limit).

[VBCurtis]

If you're concerned about the binaries, run another factorization of something around 100 digits. It'll take an hour or two, but if it completes you have reason to believe your binaries work fine.

[chris2be8]

I've had another look at the log you posted, and compared it with a successful run I did to factor a 155 digit number. I had 48059844 relations, which is less than the 57105545 relations you have for a slightly smaller number. So that's not the problem.

Nothing else looks odd to me. So re-running the -nc1 step is the next thing to try (if you havn't already).

If that fails I'm out of ideas, short of posting the relations and letting someone else try to solve them.

@jasonp, have you any suggestions?

Chris

[EdH]

Originally Posted by Timic

...
Trying EdH's now (I also included the .poly or should I remove that too?)... but I doubt it will work...

.poly is used for sieving. It is converted to .fb for msieve. Only the files referenced in the command line will be accessed initially. All other intermediate files will be created by msieve.

I don't recall if you mentioned running a separate duplicate removal tool on the relations. I know of remdups4 for linux. Maybe someone else might chime in as to whether there is a Windows version. If so, you might want to run it on the relations file, at least prior to zipping and sending, if you choose that direction.

[Timic]

I have an Intel CPU i7 3770 (new machine, where I'm trying to get through linear algebra) - third generation is Ivy Bridge so it can't be binaries. I've seen that msieve version 1.53 is available and I have version 1.52, should I try with the latest version?

I tried to factor a 100 digit composite (1522605027922533360535618378132637429718068114961380688657908494580122963258952897654000350692006139, found on Wikipedia). It took 15 minutes to sieve, but then linear algebra went up to 1500% over the last 10 minutes. Is this normal? I cancelled the job.

-> msieve -s .\test/test.dat -l .\test/test.log -i .\test/test.ini -nf .\test/test.fb -t 8 -nc1
-> Running matrix solving step ...
-> msieve -s .\test/test.dat -l .\test/test.log -i .\test/test.ini -nf .\test/test.fb -t 8 -nc2
linear algebra completed 2495058 of 163312 dimensions (1527.8%, ETA 529h 2m)

Woot

[pinhodecarlos]

Show us your task manager processes.

Can you give us access to the machine through teamviewer so we can take a look onto your files to dig out what’s going on? Or as suggested previously send us the dat file although I can only test it within 8 days.