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bio website github.com/CodesInChaos
location Frankfurt, Germany
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visits member for 3 years, 4 months
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Feb
27
comment How to efficiently generate a stream of independent, but biased random bits?
Actually an output bit has only 0.72 bits of entropy.
Feb
27
comment When do ECC patents end?
My impression is that as long as you use a software implementation of a prime curve without point compression, you're probably not violating any patents. (As usual IANAL applies)
Feb
27
comment When do ECC patents end?
See Can ECC be used without infringing on patents?
Feb
27
comment When do ECC patents end?
A lot depends on how ECC is used. Most patents cover specific aspects which many implementations don't use at all.
Feb
27
awarded  Nice Answer
Feb
27
revised Can I find two specific words with the same md5 hash?
deleted 5 characters in body
Feb
26
comment Padding always the same, problem or not?
If your messages are always a multiple of 16 bytes, you don't need padding at all.
Feb
26
answered Can I find two specific words with the same md5 hash?
Feb
25
answered Turning a cipher into a hashing function
Feb
25
comment Turning a cipher into a hashing function
CBC can be used to turn a cipher into a MAC, but not into a has. In particular if the attacker knows the key for a CBC-MAC, he can trivially find collisions/pre-images.
Feb
24
revised Why is triple-DES using three different keys vulnerable to a meet-in-the-middle-attack?
added 62 characters in body
Feb
23
comment Fastest multiplication algorithm for efficient exponentiation in C++?
How large are you numbers? For typical crypto sizes schoolbook multiplications are still pretty popular. These alternative algorithms only pull ahead for larger numbers.
Feb
22
comment Why nobody considers counter re-keying as a standard Block Cipher Mode?
@SDL Does the update do a better job at explaining the attack?
Feb
22
revised Why nobody considers counter re-keying as a standard Block Cipher Mode?
added 365 characters in body
Feb
22
revised Why nobody considers counter re-keying as a standard Block Cipher Mode?
added 469 characters in body
Feb
22
revised Why nobody considers counter re-keying as a standard Block Cipher Mode?
added 469 characters in body
Feb
22
comment Why nobody considers counter re-keying as a standard Block Cipher Mode?
Related question: Can I build a secure tweakable block cipher from a normal one by adding key and tweak?. That idea seems to be the same as yours.
Feb
22
answered Why nobody considers counter re-keying as a standard Block Cipher Mode?
Feb
22
comment Digital signatures in SSL/TLS-like protocols
You can authenticate to a specific party using DH. CurveCP is a TLS like protocol that does this.
Feb
22
comment Can I find two specific words with the same md5 hash?
Look up the chosen prefix collision attacks on MD5. | The brute-force collsion attack Jon Hulka describes if far to expensive for the OP.