Re: bits vs bytes
Arno Wagner <[email protected]>
| Newsgroups | gmane.linux.kernel.device-mapper.dm-crypt |
|---|---|
| Message-ID | <[email protected]> |
On Tue, Mar 31, 2020 at 07:35:16 CEST, JT Morée wrote: > > On Monday, March 30, 2020, 6:43:11 PM MST, Arno Wagner <[email protected]> wrote: > > Not in a cryptographic context. You could also want to etch them > > is that because the 512 bits is not the size of the key but instead a > measurement of one component that goes into generating the key? Well, block-ciphers have gotten to respect CPU operations recently, so they are starting to use bytes internally ti increase efficiency. But look at classic DES, and every but pretty much gets treated by itself or bits get grpuped in ways that have nothing to do with byte boundaries. Or look at RSA and whether you have a 4096 bit, 4095 bit or 4097 bit modulus makes no difference. Of course you usually go for multiples of 8, but that is just to accomodate a specific implementation (computers with 8 bit bytes), not anything that is part of the algebra of the cipher. Just accept it, it makes sense form a mathematical viewpoint. Otherwise you would need to multiply by 8 in a lot of places. And you could also use nibbles (4 bit) words (16 bits), long words (32 bits) or quadwords (64 bits) as "units". The byte is not really specuial. Regards, Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., Email: [email protected] GnuPG: ID: CB5D9718 FP: 12D6 C03B 1B30 33BB 13CF B774 E35C 5FA1 CB5D 9718 ---- A good decision is based on knowledge and not on numbers. -- Plato If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier _______________________________________________ dm-crypt mailing list [email protected] https://www.saout.de/mailman/listinfo/dm-crypt