On 11/15/2015 06:22 PM, Jim Starkey wrote: > On 11/15/2015 7:55 AM, Alex Peshkoff wrote: >> Presence of one surely known plain-text and corresponding encrypted >> text will be of great help to the potential attackers in such a case. > Really? Why do you think it would be a "great help." What useful > information is leaked? And how would a miscreant know a full > cipherblock of header info? > > I think what you're referring is called a "chosen plaintext" attack that > presumes the existence of an "oracle" (as in "evil") that the attacker > can submit arbitrary texts for encryption hoping to deduce something > about the key. Having a few instances of plaintext cryptotext pairs > would be sufficient to break with ZLib or LZW, but I doubt there is a > cryptosystem on the planet that is so pathetic that a handfull of known > encryptions would be of any use.
I do not refer to any known attacks, I refer to what may (theoretically) happen. > > But back to practical matters, if the guy has the key to decrypt the > headers, it's done. He's in. There's nothing more to do except moan. Header is not encrypted. Only data, index and blob pages are encrypted. Certainly, it's implementation detail, but for example crypt plugin name is stored in header. I.e. it's not very practical to have it encypted if we want engine to know that name. ------------------------------------------------------------------------------ Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
