Re: [TLS] Alert type for connection limit or server busy?

[Alyssa Rowan <[e-mail]>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

On 02/04/2014 06:44, Erik Nygren wrote:

> For example, a server under attack could propose back to clients:
> 
> { partial_value, num_bits, SHA256(full_value) }
> 
> where the first num_bits of full_value have been zeroed out.

Otherwise known as "hashcash".

It's been noted (by Satoshi Nakamoto, I think?) that you get better
granularity with "here's an integer: find me a value that hashes to
less than that" (given a particular form of integer
representation<->octets).

Of course, the server would have to spend cycles generating and
validating challenges.  Not as many as the clients, but still, cycles.

I don't think this is necessarily useful.  Might even make a DoS
surface more visible.

- -- 
/akr
-----BEGIN PGP SIGNATURE-----
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=3YuW
-----END PGP SIGNATURE-----