Re: [TLS] Salsa20 and Poly1305 in TLS

Ted Krovetz <ted@krovetz.net> Mon, 12 August 2013 01:14 UTC

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From: Ted Krovetz <ted@krovetz.net>
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Subject: Re: [TLS] Salsa20 and Poly1305 in TLS
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> Do you think the benefits of Chacha motivate
> ignoring the time that went into reviewing Salsa20?

The nice thing about Chacha is that most of the Salsa analysis applies. The only differences between the two algorithms is (1) the ordering of the initial and final 16 word state, and (2) two rotation distances. I believe that Dan Bernstein has said that he believes (1) has no security consequences and that (2) improves security.

If I were choosing between the two, yes, I'd be willing to transfer my confidence from Salsa to Chacha and  use that.

-Ted