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tptacekyesterday at 4:26 PM3 repliesview on HN

This is Sweet32, an attack on any block cipher with an 8-byte block size. We don't consider those ciphers "broken"; they just can't be used safely in some common modes. You shouldn't use 3DES or IDEA or Blowfish, of course, but I don't think they're considered "broken", not in the same sense that, say, RC4 is.


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tialaramexyesterday at 4:59 PM

It's true that 64 bits was known not to be enough when DES shipped decades ago, but there is some difference between "We know that's a bad idea" and a demo showing why, and so I think I'm OK with the word "broken" in that context.

There's a reason POCs matter right? Why you feel comfortable (even though I don't agree) saying multi-threaded Go doesn't have a memory safety problem and yet you wouldn't feel comfortable making the same claim for C++.

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_tk_yesterday at 5:52 PM

Not to be rude, but it seems to me that you are engaging in some hairsplitting. In general, security people do not recommend to use 3DES or RC4 - even if RC4 is broken in other ways than 3DES.

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zxcvasdyesterday at 4:38 PM

to any non-cryptographer, i think that's a distinction without a difference. it's disallowed from use by the major standards institute due to a vulnerability where people can recover the plain text.

that sounds "broken" to me, but i'm not a cryptographer. so, i'll defer to you when you say it's not broken. (i dont know what the cryptographer-specific definition of broken is -- it'd be great if you would shed some light on that)

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