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Feb
22
comment Post-quantum authenticated encryption
New paper claims to break GCM, CBC-MAC, OCB, etc. on quantum computer: arxiv.org/abs/1602.05973
Oct
27
awarded  Yearling
Jun
26
awarded  Caucus
Jun
26
awarded  Constituent
Jun
26
awarded  Good Answer
Mar
1
awarded  Announcer
Sep
24
awarded  Autobiographer
Jul
17
awarded  Announcer
May
2
comment A single password manager vs password generator/hash
@AdamSmith It is assumed that salt is a public value: usually password generators use site address for it, e.g. PBKDF2("master password", "google.com"). If the salt is secret (let's call it a "secret seed", because salt is reserved for a different term) and has enough entropy (e.g. 128 bits), then it's infeasible to guess the master password. However, this is not the scheme discussed here (deriving many passwords from a single one), as the user has to remember a random value along with the master password for it to work.
Apr
29
comment A single password manager vs password generator/hash
@AdamSmith the difference between bruteforcing/running dictionary attack on encrypted password database and a hash of the generated password is only in the cost of the hash operation. E.g. if password database is encrypted with a key derived with PBKDF2-HMAC-SHA256 with 100,000 iterations and the password generator generates passwords by running 100,000 iterations of PBKDF2-HMAC-SHA256, and a website that leaked passwords uses bcrypt to hash passwords, then guessing the master password for password generator (bcrypt(PBKDF2-SHA256(master_password))) is only harder for the cost of bcrypt.
Oct
16
awarded  Excavator
Oct
16
revised Examples of applications that use the Schnorr digital signature?
OpenSSL -> OpenSSH
Oct
15
suggested approved 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 approved 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/…