Noob Question: What to use

[bozocv]

I am new here and new to factoring also.

I own AMD 5870 GPU and core i5 4690. Win 7 64bit.

Is there a version of msive that I can run on my GPU and would it be faster than on my CPU?

I want to factor 154 decimal digit number first 3 digits 299.

[VictordeHolland]

You might want to start with YAFU.

[Batalov]

Originally Posted by bozocv

I want to factor 154 bit number first 3 digits 299.

154 bit number?
or
154 decimal digit number?
The answers will be quite different as to which tool to use.

For 154-bit - you will get an almost instantaneous factorization with yafu, or you can paste it into www.factordb.com and some computations will be run for you by its engine.

[bozocv]

Originally Posted by VictordeHolland

You might want to start with YAFU.

May I ask why you suggest YAFU?

[bozocv]

@Batalov

154 decimal digit... sorry.

[Batalov]

For 154-digit number you need to go over some tutorials, e.g.
http://gilchrist.ca/jeff/factoring/n...ers_guide.html

[bozocv]

I started it like this:

msieve -v -e 0x392D649F152B84CCE79DD50B63DA0BDDEC57A5A3DF1D2327730A14
FCC1331F7590033D7D9358EC13DA510B3972F520069C62C5E6E438912DB8192207474C35B6

[VBCurtis]

Originally Posted by bozocv

May I ask why you suggest YAFU?

YAFU makes a bunch of decisions for you about what parameters to use, and manages each of the tools used to produce the factorization. 154 digits is a big job for YAFU, but it will work. YAFU does not use the GPU-enabled version of msieve, but the GPU is only used for one part of one step; you might save half a day using the GPU yourself, but you'd likely spend half a day in human time learning how to do it all.

Batalov's suggestion is where to begin in order to understand what is happening at each step of the way, and is strongly recommended if you plan to factor more than a single number. That is, the more you learn the more effective your use of the tools will be, but for a single job it's unlikely you'll gain much over YAFU in terms of speed the job completes. Once you get YAFU set up correctly (for instance, telling it how many cores to use), expect about 8-12 days using all cores to complete the factorization.

[LaurV]

Originally Posted by bozocv

I started it like this:

msieve -v -e 0x392D649F152B84CCE79DD50B63DA0BDDEC57A5A3DF1D2327730A14
FCC1331F7590033D7D9358EC13DA510B3972F520069C62C5E6E438912DB8192207474C35B6

Interesting... What online game are you trying to break?

[VBCurtis]

I thought 512-bit keys were left in the PS2/TI89 era. Hrmph.
I, too, wonder what game this is!

[debrouxl]

Before RSALS was created, the first TI-Z80 / TI-68k 512-bit RSA public key factorizations used Jeff Gilchrist's NFS Beginners Guide and factMsieve.pl.

Another option is to set up your own copy of the "Factoring as a Service" infrastructure, http://seclab.upenn.edu/projects/faas/ . Its throughput shall trounce your computer's, but cost more.

In this day and age, 512-bit RSA keys are laughably easy to break...