9,751 reputation
12448
bio website github.com/CodesInChaos
location Frankfurt, Germany
age
visits member for 3 years, 2 months
seen 4 hours ago

Sep
13
comment Is there a method to break an EC curve for all key-pairs (Q,d) such that (Q=d*G) faster than breaking every single key-pair?
The problem with this is that you're assuming separate pre-calculation and lookup phases. A single phase multi-target attack is an important scenario too, where you simply want to crack one of a million known public keys. I believe the gain in that scenario is still rather small, but it exists.
Sep
13
revised Structure of encrypted office files
deleted 35 characters in body
Sep
12
reviewed Approve suggested edit on PBKDF2 and salt
Sep
12
comment How to encrypt data and know it will be secure for at least a few decades?
tahoe-lafs.org/trac/tahoe-lafs/wiki/OneHundredYearCryptography
Sep
8
revised Is it safe to use file's hash as IV?
added 1 characters in body
Sep
8
revised Is it safe to use file's hash as IV?
added 176 characters in body
Sep
8
answered Is it safe to use file's hash as IV?
Sep
8
comment Can I combine two of SHA-3 candidates cryptography hash functions and obtain more secure Algorithm?
What are you using the hash function for? Only integrity checking? Then concatenating the hashes should work. (Obviously makes the hash longer)
Sep
7
revised find solutions that solve the equations
added 8 characters in body
Sep
7
revised find solutions that solve the equations
added 10 characters in body
Sep
7
revised find solutions that solve the equations
added 78 characters in body
Sep
7
comment find solutions that solve the equations
@blejzz The best increase would be 1. You simply want to try the smallest $Y$s first, since those have the highest success chance.
Sep
7
revised find solutions that solve the equations
added 150 characters in body
Sep
7
revised find solutions that solve the equations
added 150 characters in body
Sep
7
comment find solutions that solve the equations
Do you have a typo in the condition for $Z$? The $*Z>Z$ part is weird.
Sep
7
answered find solutions that solve the equations
Sep
7
comment S-box design criteria and random sboxes
At least in the case of DES, the s-boxes were stronger than random boxes, since the NSA modified them to make them more resistant to differential cryptoanalysis.
Sep
6
reviewed Approve suggested edit on Encrypting small values with RSA private key
Sep
6
comment Is it possible to pick your Ed25519 public key?
I believe the root question is: "Can an attacker impersonate a known public key by creating a keypair with a similar looking public key, for which he can execute private key operations such as signing or diffie-hellman." The actual representation of the private key is irrelevant.
Sep
6
comment Is it possible to pick your Ed25519 public key?
Your talking about "multiplicate inverse" is still weird. AFAIK there is no operation that multiplies two points on a curve. There is only an operation that multiplies a scalar with a curve point. If you look at the analogous operation in a finite field $B^{a'}=A'$, you can't find an inverse element for $B$ either.