8,789 reputation
12041
bio website github.com/CodesInChaos
location Frankfurt, Germany
age
visits member for 2 years, 9 months
seen 12 hours ago

Dec
17
revised Can the encryption exponent e be greater than ϕ(N)?
added 230 characters in body
Dec
17
answered Can the encryption exponent e be greater than ϕ(N)?
Dec
17
comment Why is h(m||k) insecure?
Related Attacks of the MAC construction H(m||k) for common hashes H?
Dec
16
answered Good enough deterministic PRNG based on hashes
Dec
16
comment Is there a big RSA Data Set
What do you need that set for? Since you want private keys too, the easiest solution is generating such a set yourself.
Dec
14
revised How do unkeyed hash functions (for MDCs) provide security?
edited tags
Dec
14
revised How do unkeyed hash functions (for MDCs) provide security?
Added link to an attack on hash+encrypt
Dec
14
comment Public keys and their protocols
But if there are two different doors $D_1$, $D_2$, then one of the doors is able to impersonate the supervisor to the other door.
Dec
13
comment RSA blind signatures in practice
@Denis Simply don't use the same key for blind signatures and encryption/normal signatures.
Dec
13
comment Polynomials and efficient computability
"otherwise we would see much larger RSA keys in use" I wouldn't conclude that. Those definitions are asymptotic and don't say anything about concrete key sizes.
Dec
12
reviewed Approve suggested edit on Information leakage in real-time voice encryption
Dec
12
reviewed Approve suggested edit on Differential Cryptanalysis of FEAL-4
Dec
12
reviewed Approve suggested edit on What is an oracle adversary?
Dec
12
comment RSA blind signatures in practice
@Denis No the bank doesn't pad. The applicant pads before blinding.
Dec
12
comment Can a shift cipher attain perfect secrecy?
@Eric Even if you treat each letter as a single message, you get the requirement that you can't send more than one message using a fixed key.
Dec
12
comment RSA encryption with private key and decryption with a public key
@PiotrDobrogost Check PKSC#1 for secure padding schemes.
Dec
11
comment RC4 encryption -> AES encryption = more or less secure than RC4 or AES alone?
I'd rather combine AES and Salsa20 than AES and RC4. And you did not specify what you mean by "encrypt with AES". Blockciphers don't simply encrypt data, you need a chaining mode. And what about IVs?
Dec
11
comment RC4 encryption -> AES encryption = more or less secure than RC4 or AES alone?
"you will have plenty of time to migrate away from the affected cipher" While you can upgrade authentication, you can't really upgrade confidentiality, since an attacker can simply store the old ciphertext. So in many scenarios you need a time-machine to do that.
Dec
11
comment What are the differences between a digital signature, a MAC and a hash?
One interesting variation is using the result of a DH key exchange as the key for a MAC. That way you can use asymmetric keys, but you avoid non-repudiation.
Dec
11
comment RSA blind signatures in practice
The main difference between blind and normal signatures is that the adversary creates the padding for a blind signature. So I'd prefer some kind of deterministic padding (such as FDH), since it reduces the freedom of the attacker.