Re: Mersenne: Crypto scientists crack prime problem, not Redmond journalists
Nathan Ranks wrote: > > Is it just me, or am I missing something? If you multiply any two numbers > together, the resulting number can't be prime since it would be divisible by > both the two numbers used... > > Prime = divisible by itself and 1 Quite so! That's why we are concerned that such an article should be published widely. I apologise unreservedly for any suggestion I may have made that the article was written by anyone in Redmond, and acknowledge Paul's comments on this matter. Regards, Ian -- Ian W Halliday, BA Hons, AAIBF Snr, ATMS, CL +64 27 245 6089 (GMT+12) http://baptism.co.nz ; http://ringbark.livejournal.com Focus On Success -- Word documents not accepted -- see http://baptism.co.nz/word.html _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Question about setting available memory
At 07:16 AM 8/17/2002 -0700, Gary Edstrom wrote: >It is my understanding from reading the documentation that setting the >available memory only affects the P-1 factoring stage and not the main >LL test. Is this correct? Yes. >The reason I am asking is because of a great difference that I have >noticed in the iteration time of the LL test on my 2.2GHz desktop and my >1.0GHz laptop while running comparable sized numbers on both machines. >I would expect to see the laptop taking a little more than double the >iteration time of the desktop. Instead, I am seeing a 5x difference. The P4 2.2GHz machine uses the SSE2 instructions for a big speed up. See the http://www.mersenne.org/bench.htm for timings from a wide variety of machines _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Crypto scientists crack prime problem, not Redmond journalists
On Saturday 17 August 2002 03:22, Halliday, Ian wrote: > In http://msn.com.com/2100-1104-949170.html?type=pt we read > > Crypto scientists crack prime problem > > To create encryption keys, RSA uses two huge prime numbers and > multiplies them together to produce an even bigger prime. The hard problem RSA relies upon is not finding whether a number is prime, but finding its factors if it isn't. But someone who thinks that the product of two prime numbers is prime doesn't know the difference. Then there's the discrete logarithm problem, which he probably doesn't know from the concrete logrolling problem. phma _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Crypto scientists crack prime problem, not Redmond journalists
Is it just me, or am I missing something? If you multiply any two numbers together, the resulting number can't be prime since it would be divisible by both the two numbers used... Prime = divisible by itself and 1 - Original Message - From: "Halliday, Ian" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, August 17, 2002 2:22 AM Subject: Mersenne: Crypto scientists crack prime problem, not Redmond journalists > In http://msn.com.com/2100-1104-949170.html?type=pt we read > > Crypto scientists crack prime problem > > To create encryption keys, RSA uses two huge prime numbers and > multiplies them together to produce an even bigger prime. > > Regards, > > Ian > -- > Ian W Halliday, BA Hons, AAIBF Snr, ATMS, CL > +64 27 245 6089 (GMT+12) > http://baptism.co.nz ; http://ringbark.livejournal.com > Focus On Success > -- > Word documents not accepted -- see http://baptism.co.nz/word.html > _ > Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm > Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Question about setting available memory
At 07:16 AM 8/17/02 -0700, you wrote: >It is my understanding from reading the documentation that setting the >available memory only affects the P-1 factoring stage and not the main >LL test. Is this correct? > >The reason I am asking is because of a great difference that I have >noticed in the iteration time of the LL test on my 2.2GHz desktop and my >1.0GHz laptop while running comparable sized numbers on both machines. Clock speed is not the only determinant. Chip internals have a lot to do with it, too. Cache size, instruction set, RAM type and speed all affect iteration time. That's a 2.2 Ghz P4, and what chip in the notebook? The P4 has SSE2 instruction sets, which make it faster than, say, an Athlon 2.2Ghz (if such existed). If it's a Celeron, the cache is smaller, making it even slower. >The desktop is a Pentium IV while the laptop is a III. Could this >account for the difference? Absolutely. SSE and cache both conspire against the comparison, as may the RAM in the notebook. _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Question about setting available memory
It is my understanding from reading the documentation that setting the available memory only affects the P-1 factoring stage and not the main LL test. Is this correct? The reason I am asking is because of a great difference that I have noticed in the iteration time of the LL test on my 2.2GHz desktop and my 1.0GHz laptop while running comparable sized numbers on both machines. I would expect to see the laptop taking a little more than double the iteration time of the desktop. Instead, I am seeing a 5x difference. The desktop is averaging 48 msec The laptop is averaging 250 msec Can anyone explain this? The available memory setting on my laptop is 64MB 24 hours per day, while my desktop is set at 192MB 24 hours per day. I have 1GB of memory on the desktop, so I can afford 192MB. The desktop is a Pentium IV while the laptop is a III. Could this account for the difference? Thanks, Gary _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Re: Mersenne: Crypto scientists crack prime problem, not Redmond journalists
- Original Message - From: "Halliday, Ian" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Saturday, August 17, 2002 8:22 AM Subject: Mersenne: Crypto scientists crack prime problem, not Redmond journalists > In http://msn.com.com/2100-1104-949170.html?type=pt we read > > Crypto scientists crack prime problem > > To create encryption keys, RSA uses two huge prime numbers and > multiplies them together to produce an even bigger prime. So take any Mersenne prime, and multiply by a Fermat prime to obtain a new larger Mersenne prime. Rinse and repeat. Why didn't we think of that? > Regards, > > Ian Daran _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
RE: Mersenne: Crypto scientists crack prime problem, not Redmond journalists
Hey, please ascribe criticism where it's due. The article was written by a ZDNet journalist, as clearly stated on the MSN page. ZDNet is a subsidiary of CNET Networks, which is based in San Francisco. Same country, same coast, a lot further south. The comment by a computer scientist part way down the article is also pretty funny. Paul > -Original Message- > From: Halliday, Ian [mailto:[EMAIL PROTECTED]] > Sent: 17 August 2002 08:22 > To: [EMAIL PROTECTED] > Subject: Mersenne: Crypto scientists crack prime problem, not > Redmond journalists > > > In http://msn.com.com/2100-1104-949170.html?type=pt we read > > Crypto scientists crack prime problem > > To create encryption keys, RSA uses two huge prime numbers and > multiplies them together to produce an even bigger prime. > > Regards, > > Ian > -- > Ian W Halliday, BA Hons, AAIBF Snr, ATMS, CL > +64 27 245 6089 (GMT+12) > http://baptism.co.nz ; http://ringbark.livejournal.com > Focus On Success > -- > Word documents not accepted -- see http://baptism.co.nz/word.html > __ > ___ > Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm > Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers > _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
Mersenne: Crypto scientists crack prime problem, not Redmond journalists
In http://msn.com.com/2100-1104-949170.html?type=pt we read Crypto scientists crack prime problem To create encryption keys, RSA uses two huge prime numbers and multiplies them together to produce an even bigger prime. Regards, Ian -- Ian W Halliday, BA Hons, AAIBF Snr, ATMS, CL +64 27 245 6089 (GMT+12) http://baptism.co.nz ; http://ringbark.livejournal.com Focus On Success -- Word documents not accepted -- see http://baptism.co.nz/word.html _ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
