If you believe that "don't roll your own crypto" is some kind of absurd mantra the security industry uses to keep us in business, I recommend that you roll your own crypto, and keep us in business.
How far should we take that maxim? It implies that no one should ever attempt this, but that leads to nothing new (unless you are first recognised as a crypto guru -- but how could you become one?). I think it's worth drawing a distinction between the algos/maths and attempts at implementations. Otherwise we wouldn't have things like OCaml-TLS and others. http://openmirage.org/blog/introducing-ocaml-tls
The Cryptographic Doom Principle
131–140 of 140 posts
Re: The Cryptographic Doom Principle
#132Earlier quoted context omitted.
That seems ridiculous for 2 reasons. First, ciphertext is ciphertext. They'd probably be able to determine it's a block cipher and what the block size is, but that's about it. They're not going to be able to tell AES ciphertext from 3DES ciphertext if they're both set to use the same block size. There's no point "obscuring" the fact that you're using AES. Second, if you're assuming the NSA seriously has the capabilit…
First, ciphertext is ciphertext. They'd probably be able to determine it's a block cipher and what the block size is, but that's about it. You can tell mode somewhat reliably (I've hit 75% confidence or so) by the entropy content of the ciphertext, and I've never done a Markov chain longer than a native word so I'd assume that gets better the longer your chain is. I would also assume people much smarter than me have…
Re: The Cryptographic Doom Principle
#133If you believe that "don't roll your own crypto" is some kind of absurd mantra the security industry uses to keep us in business, I recommend that you roll your own crypto, and keep us in business.
How far should we take that maxim? It implies that no one should ever attempt this, but that leads to nothing new (unless you are first recognised as a crypto guru -- but how could you become one?). I think it's worth drawing a distinction between the algos/maths and attempts at implementations. Otherwise we wouldn't have things like OCaml-TLS and others. http://openmirage.org/blog/introducing-ocaml-tls
Re: The Cryptographic Doom Principle
#134Earlier quoted context omitted.
Um, no. http://w3techs.com/technologies/overview/programming_languag... Currently 82%, last time I checked it was 83%.
It slightly decreases the validity of the page when it states that ASP.NET is a programming language.
Seriously, just assume they mean technology stack or something.
Re: The Cryptographic Doom Principle
#135Earlier quoted context omitted.
Thank you for the link and the review. I start my CS degree in the Fall; i hope i can start and finish this before then.
For the love of all that is sacred, take advanced math and linear algebra.
Re: The Cryptographic Doom Principle
#136Earlier quoted context omitted.
So I think it comes down to whether the root > I think there's a more fundamental cryptographic principle. Don't implement cryptography, unless you are an absolute top expert. is a sound advice. I disagree with this advice strongly. Tinkering around with cryptography can teach you a lot. Especially if you are not a top expert. Furthermore, I described a relatively simple protocol that monotonically increases the secu…
I described a relatively simple protocol that monotonically increases the security of a communication Careful. Encryption is decryption, remember. Do any of the rounds of CC undo any of the rounds of KC? Can you verify that bits that were correlated in PT and uncorrelated in KC are still uncorrelated in KC + CC? Does CC change the entropy content of the resulting message? (If it decreases it you have a problem, and m…
Re: The Cryptographic Doom Principle
#137If you believe that "don't roll your own crypto" is some kind of absurd mantra the security industry uses to keep us in business, I recommend that you roll your own crypto, and keep us in business.
Schneier's Law comes to mind "Anyone, from the most clueless amateur to the best cryptographer, can create an algorithm that he himself can't break." https://www.schneier.com/blog/archives/2011/04/schneiers_law...
Re: The Cryptographic Doom Principle
#138Earlier quoted context omitted.
How far should we take that maxim? It implies that no one should ever attempt this, but that leads to nothing new (unless you are first recognised as a crypto guru -- but how could you become one?). I think it's worth drawing a distinction between the algos/maths and attempts at implementations. Otherwise we wouldn't have things like OCaml-TLS and others. http://openmirage.org/blog/introducing-ocaml-tls
Maybe people can show new stuff they make on HN etc before using it in their apps.
Re: The Cryptographic Doom Principle
#139If you believe that "don't roll your own crypto" is some kind of absurd mantra the security industry uses to keep us in business, I recommend that you roll your own crypto, and keep us in business.
Schneier's Law comes to mind "Anyone, from the most clueless amateur to the best cryptographer, can create an algorithm that he himself can't break." https://www.schneier.com/blog/archives/2011/04/schneiers_law...
Re: The Cryptographic Doom Principle
#140Earlier quoted context omitted.
The output of KC is not necessarily completely random. It can contain some metadata. Like "encrypted with KC4096bits, initialization vector is 490282348992489, length of ciphertext is 26728 bytes". When you pass this through a bad cipher it may create a characteristic fingerprint.
I think you confuse cipher with protocol. To make it clear: for me a cipher is a bijective function on arrays of a predefined length.