With regard to the changelog, saying CBC ciphers are unsafe is pretty misleading. CBC implemented properly is rock-solid (against a certain subset of attacks with for a certain definition of rock-solid that does include an epsilon term for attacker advantage). It’s just slower and easy to mess up in certain ways (although CTR and CTR-based modes in general are far from foolproof, for instance, reusing a nonce compromising the whole plaintext, instead of just metadata)

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One interesting fact about padding oracle attacks (the family of attacks to which poodle belongs) is that they only work on CBC-mode block ciphers. CTR-mode, an alternative mode of operation that essentially changes a block cipher to a stream cipher, cannot be vulnerable to this kind of attack (and has the added benefit of being easily parallelizable), but has suffered from a lack of adaption due to some misunderstandings. As @journeysquid noted, OpenSSH has now actually disabled CBC ciphers in general, which is probably a good idea.

Note: You probably shouldn’t actually use CTR mode for anything, is it doesn’t provide authentication, but in a situation where you’re choosing between CTR and CBC, choose CTR

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UChicago is definitely on my list of places to apply! I’m actually fairly geographically close, and I love the ethos of the school in general

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This week I’m still slowly moving forward on my timing attack resistant type systems project. I’ve been working on a proof-of-concept implementation of the Montgomery ladder, but it’s tricky figuring out what “counts” as an operation that will take time without full-on writing an x86 CPU in idris, which I want to avoid. I think for now I’m just going to assume that anything in the x86 instruction set counts as one action, but I’m not sure that’s the right decision. If anyone good at crypto or idris who also knows their low-level stuff better than I do has some advice, I’d love to hear it.

Applying to college is still in the planbook as well, and I’ll be finishing phase two of my Minerva application today and tomorrow, after which I’m beginning to really work on my common app. I’m still looking for colleges as well, so if any of you happen to go to or know of a school with a CS program you really love, I would love to know about it.

Aside from that, I’ve been helping to organize a STEM-y merit badge day for local boy scouts with the local chapter of the Order of the Arrow, the hackerspace in town, and our local university’s security club, and that’s been coming along nicely, so it’s cool to see all of that shape up. I finally got all my location stuff worked out, and now I’m just praying no more people who signed up to help out cancel and trying to find replacements for those who did.

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