Thus spake Sarad AV (jtrjtrjtr2001@yahoo.com) [05/04/05 13:46]: : hi, : : news below: : : http://www.net4nowt.com/isp_news/news_article.asp?News_ID=2809 : : : Google is way too fast. Whats the difference seraching : using google in 10 milliseconds and in 5 : milliseconds?Perhaps they are taking some load off : their server? I fail to see how it is useful to the : search client. The difference is not in the search, but in the clicking on the results. Say the result you want /is/ the first one: this way, when you click on it, the page loads up faster.

On Apr 7, 2005 10:13 AM, Sarad AV <jtrjtrjtr2001@yahoo.com> wrote:

hi,

I am a little confused after reading this:

http://www.rsasecurity.com/rsalabs/cryptobytes/CryptoBytes_January_2002_fina...

RSA-CRT decryption is nearly four times faster than using only modular exponentiation for decryption. Is Rebalanced-RSA-CRT three times faster in decryption than RSA decryption only using modular exponentiation or is it three times faster than RSA-CRT in decryption?

It has to be the second one. If it were only 3 times faster than vanilla RSA, while RSA-CRT was 4 times faster than vanilla, then rebalanced would not be a speedup over the usual way of doing things. Rebalanced RSA is 3 times faster than RSA-CRT. What "rebalanced RSA" means is that you choose the private exponent d so that exponentiation with it is fast. This speeds up decryption at the expense of encryption. You can't just choose a small d; this is known to be insecure. Instead they propose to choose a d such that the two exponents in the CRT, d mod p-1 and d mod q-1, are relatively small, about 160 bits. This gives a factor of 3 speedup vs the usual 512 bit exponent in 1024 bit RSA-CRT. Is this safe? Who knows? I wouldn't recommend using it until Don Coppersmith chewed on it for a while. He's the guy who pushes the state of the art on small-d attacks. I'd wait for his opinion on whether this variant on small-d escapes his attacks.