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Comment by tptacek | Hacker News Reader

It is extraordinarily unlikely that Speck is backdoored, since it's a (deliberately) simple ARX block cipher transform, a close cousin to a variety of other block cipher designs from academic cryptography.

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Yeah, https://lwn.net/Articles/762152/ has a full source code to Speck. It's like - OK, where is the backdoor, is eight the backdoor, or is three? Did the NSA sneak a backdoor into the idea of binary arithmetic when that was invented?

If people want to pick fights with the NSA, fine, but this may have been the dumbest possible fight to pick.

How does the implementation of HPolyC look in terms of whether I would notice if you hid something naughty in there?

Speck was announced to the world in a paper with design documentation, diagrams, and source code. Just read the Shors paper.

https://eprint.iacr.org/2017/560

Nobody is hiding anything in HPolyC either.

My concern wasn't with speculating that anybody is hiding anything in HPolyC but with the comparable amount of code amongst which naughty things might be hidden, today or in future, in Linux, or more likely, in something else.

Unfortunately HPolyC is _much_ bigger and more complicated. I'm sure it gets Google's job done, but I think overall purging Speck because of people's weird paranoia about the NSA was an unforced error and we'll regret it.

HPolyC is "bigger" but is built out of cryptographic components you generally already have to trust: the Poly1305 MAC and the XChaCha cipher. It's a construction, not a new block cipher transform. So obviously it takes more lines of code to run it. But it introduces fewer new primitives.

There's nowhere to hide a backdoor in TEA either.

There isn't, though misuse of TEA helped break the XBox security model.

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