Comment by dchest | Hacker News Reader

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Comment by dchest | Hacker News Reader

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From https://www.balboa.io/security.html:

"Skein-1024-CTR, with Skein-1024 as an HMAC in an encrypt-then-mac scheme"

I guess Skein-CTR is based on "Skein as a Stream Cipher" section from the spec.

https://github.com/pkcsecurity/trabant/blob/master/pkc_skein...

From homepage: "We use 1024-bit symmetric key encryption, a stronger level of encryption than most industry standards."

I guess the reason for using Skein is so that they can use this bullshit marketing :)

"1024-bit symmetric key encryption" certainly has the flavor of a statement which is technically correct, but designed to be favorably misinterpreted. I'm surprised they didn't mention that Skein is gluten free.

Skein HMAC? Why? Skein was designed not to need the HMAC construction.

It looks like they are actually using keyed Skein and call it HMAC

https://github.com/pkcsecurity/trabant/blob/master/pkc_skein...

You're right. To be honest, the reason why we don't use it the way it is described in the paper, is entirely out of fear of misconfiguring the Skein context. The NIST reference implementation for Skein doesn't provide a simple way or an example for building the valid configuration for the HMAC construction they recommend, and we always wanted to feel like we had a wall to our back (i.e. being able to check against the NIST implementation or to check against test vectors). They do mention in the paper that doing the keyed mac approach is provably safe, which just felt easier to implement.

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