Re: Arcfour in Ada

["Julian Morrison" <julian@extropy.demon.co.uk>]

"Thomas Boschloo" <nospam@multiweb.nl> wrote:

> Why did you decide to go for arcfour and not the AES
> http://www.nist.gov/aes ?
> [...]
> 
> AES seems so much more secure in the long run than RC4!

AFAIK, the AES cypher is more secure in that you can safely reuse keys.
It's also newer, though, and new crypto is less trustable. AES is also a
very gread deal more CPU churn and overhead than Arcfour. Since you can
only encrypt in blocks of four bytes, you need extraneous header info to
show where the contents end, and you need to CBC the blocks together. If
you're encrypting a lot of small things (such as in Fling's routeballs)
the overheads will add up.

From what I've understood from older messages here, Arcfour is "good
enough" for the task at hand. Of course, if anyone knows I got this
wrong, please do say.