538 reputation
411
bio website codingrobots.com
location
age 31
visits member for 2 years, 8 months
seen Jan 10 at 10:34
Programmer and founder at Coding Robots

Oct
16
awarded  Excavator
Oct
16
revised Examples of applications that use the Schnorr digital signature?
OpenSSL -> OpenSSH
Oct
15
suggested suggested edit on Examples of applications that use the Schnorr digital signature?
Aug
3
awarded  Yearling
Apr
25
revised Tamper-proofing log files
Fixed link
Apr
25
suggested suggested edit on Tamper-proofing log files
Mar
31
comment Single-purpose symmetric encryption scheme for single files
@StephenTouset no, it uses MD5. See github.com/Chronic-Dev/openssl/blob/master/apps/enc.c#L552 and openssl.org/docs/crypto/… or stackoverflow.com/questions/9488919/openssl-password-to-key. Also, the output format doesn't seem to be documented.
Mar
30
comment Single-purpose symmetric encryption scheme for single files
Have you seen the file format of scrypt utility? It's a good reference on how to do it properly: code.google.com/p/scrypt/source/browse/trunk/FORMAT
Mar
30
comment Single-purpose symmetric encryption scheme for single files
@StephenTouset proper key derivation?
Mar
13
comment Security of tokenization of plain text conversations - cryptanalysis
See also crypto.stackexchange.com/questions/3645/…
Mar
9
comment ChaCha cipher + Poly1305
I think you're referring to hashing the result of DH. djb says you should hash the result of curve25519 scalar multiplication before using it ("Both of you can then hash this shared secret and use the result as a key for, e.g., Poly1305-AES." cr.yp.to/ecdh.html), so crypto_box uses HSalsa as a hash function for shared key. Crypto_secretbox doesn't have this step.
Mar
8
comment ChaCha cipher + Poly1305
HSalsa is used to turn Salsa20 (8-byte nonce) into XSalsa20 (24-byte nonce) as per "Extending the Salsa20 nonce" paper: cr.yp.to/snuffle/xsalsa-20081128.pdf
Jan
26
revised Using UMAC with stream cypher
added 139 characters in body
Jan
26
answered Using UMAC with stream cypher
Jan
26
revised Hashing passwords with a salt - why use different salt for everyone?
s/getting/building/
Jan
26
revised Hashing passwords with a salt - why use different salt for everyone?
Rephrase the whole answer
Jan
26
comment Hashing passwords with a salt - why use different salt for everyone?
Again, the question was: are there drawbacks in the system where we don't use /dev/urandom to generate salts? I listed them. I'll try to rephrase my answer.
Jan
26
comment Hashing passwords with a salt - why use different salt for everyone?
This answer to a bit different question on Security StackExchange is very good: security.stackexchange.com/questions/11221/…
Jan
26
revised Hashing passwords with a salt - why use different salt for everyone?
Highlight the main point.
Jan
26
comment Hashing passwords with a salt - why use different salt for everyone?
I considered the case of changing passwords later in the answer. We get system which leaks some information about passwords if there are multiple leaks of database. Is it bad? Yes. Is it better than a single per-database salt? Yes. Is it worse than random salt? Of course.