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This is a good illustration of how, 1) crypto is hard 2) real-world cryptosystem design & implementation is hard and 3) teaching the aforementioned is hard. I

by zurn 13y ago

This is a good illustration of how, 1) crypto is hard 2) real-world cryptosystem design & implementation is hard and 3) teaching the aforementioned is hard. I read Schneier's & Ferguson's Practical Cryptography years ago, the only thing I remember about it is the "don't try this at home" message.

Nursie 13y ago
I recommend Dan Boneh's coursera course, Crypto I, to get a good (basic) grounding in how some of this stuff works. He shows just how easy it is to break bad crypto systems in unexpected ways, and he does it by leading you through 5he attacks and getting you to implement some. Was rather impressed...
mehrdada 13y ago
> I read Schneier's & Ferguson's Practical Cryptography years ago I cannot take anyone who advocated MAC-then-Encrypt, in 2010, seriously (in the book Cryptography Engineering: Design Principles and Practical Applications by Niels Ferguson, Bruce Schneier, Tadayoshi Kohno). The school of cryptography they subscribe to seems to be "crypto is black magic; this is tried and it works and it is pretty much secure because I feel it is secure; experience is everything; proofs can have bugs too" as opposed to a more principled, analytical, methodical, provable security. This is especially problematic in pedagogical contexts, because the learners, by definition, do not have much experience or calibrated feelings, so they'll be lost or have to copy the design decisions of the authors without taking into account the contexts or that they might be flat wrong. That approach indeed implies the natural advice to someone who wants to learn will be "don't try it at home".
icambron 13y ago
"Don't try this at home" is good practical advice for building real systems that have real users. It's terrible pedagogy, though. You have to learn somehow, and trying it at home is actually how you do that.
stcredzero 13y ago
Well, the message should be, do try this at home, as an exercise, but don't put it into production!

by zurn 13y ago

Nursie 13y ago

I recommend Dan Boneh's coursera course, Crypto I, to get a good (basic) grounding in how some of this stuff works. He shows just how easy it is to break bad crypto systems in unexpected ways, and he does it by leading you through 5he attacks and getting you to implement some. Was rather impressed...

mehrdada 13y ago

> I read Schneier's & Ferguson's Practical Cryptography years ago I cannot take anyone who advocated MAC-then-Encrypt, in 2010, seriously (in the book Cryptography Engineering: Design Principles and Practical Applications by Niels Ferguson, Bruce Schneier, Tadayoshi Kohno). The school of cryptography they subscribe to seems to be "crypto is black magic; this is tried and it works and it is pretty much secure because I feel it is secure; experience is everything; proofs can have bugs too" as opposed to a more principled, analytical, methodical, provable security. This is especially problematic in pedagogical contexts, because the learners, by definition, do not have much experience or calibrated feelings, so they'll be lost or have to copy the design decisions of the authors without taking into account the contexts or that they might be flat wrong. That approach indeed implies the natural advice to someone who wants to learn will be "don't try it at home".

icambron 13y ago

"Don't try this at home" is good practical advice for building real systems that have real users. It's terrible pedagogy, though. You have to learn somehow, and trying it at home is actually how you do that.

stcredzero 13y ago

Well, the message should be, do try this at home, as an exercise, but don't put it into production!