Re: Security Practices

David Busby wrote:
> List,
>   I'm trying to get my a sshd setup as secure as possible, some folks I 
> know what to send financial data over this.
...
> aes256-cbc cipher (only)

http://cr.yp.to/antiforgery/cachetiming-20050414.pdf

You may want to be aware of this paper.  I believe the results are still 
preliminary, but it's something to follow.

> I'm thinking that 
> I'll make my key 4096bits to add some security.

Heh, is your name Avi? (cryptonomicon reference, couldn't resist) 
That's probably overkill, but that assumes no codebreaking paradigm 
shifts or what have you.

> Assume best means most secure even at
> the sacrifice of performance.  Thanks!

If you're going to use 4096 bit keys, you may want to move away from md5 
as a hashing algorithm, since it has been shown to have some measure of 
weakness.  You might look at SHA256, SHA512, or something like 
whirlpool.  I'm not an expert, however, and I'm not sure how proven 
whirlpool really is (or about the measure of support of these hashes in 
ssh).

> /djb

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:wq