ved...@hush.com wrote: > "assuming a brute force attack is feasible in real time, how could > one design a cipher that is invulnerable to brute force attack > (other than an OTP )?"
You don't. > (1) [as explained in the Digital Fortress book] what if the > decryption program didn't know when it had successfully decrypted ... >From a computational theory perspective, this means putting decryption into PSPACE. Once you leave NP behind you, your next stop is the one-time pad. > (a) change the ciphertext, and let the brute force machine merrily > try to crack the wrong ciphertext Delivering a false message to your enemies is a classic tactic in the history of communications security. In recent history, that's how we knew to intercept the Japanese fleet at Midway Island. Going back to classical history, it's one of the ways Belisarius kept the Germanic tribes divided, facilitating his successes during the reign of Justinian. > anyway, for me, the book presented interesting crypto concepts that > would be fascinating if explored ... To the extent people are inspired by it to think critically about crypto, I'm glad. But I cannot recommend it be read as an exposure to concepts in crypto. _Cryptonomicon_ (and Jon Evans' _The Blood Price_, which I should've listed on my recommended books before) are much better for that. _______________________________________________ Gnupg-users mailing list Gnupg-users@gnupg.org http://lists.gnupg.org/mailman/listinfo/gnupg-users