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14h
comment Is it possible to find out whether a number is greater than another number without knowing the numbers?
Do you need to compare each number in a pair only once, or multiple times?
1d
comment Is it possible to hand-negotiate an SSL/TLS session?
No, it is not feasible or even theoretically possible to connect to a server on 443 and type yourself through an entire SSL handshake.
Sep
15
comment What is the technical name for a public key container in DER format?
If it's not a plain PKCS#1 RSAPublicKey, it is probably a SubjectPublicKeyInfo from PKIX/X.509
Sep
15
comment What is the technical name for a public key container in DER format?
Well, you don't have to take my word for it. All you have to do is to implement a Base64 decoder, an ASN.1 parser, a DER parser and see for yourself, just like I did. :)
Sep
15
comment What is the technical name for a public key container in DER format?
The format is PKCS#1 with PEM encoding. Your question is however off topic here.
Sep
15
comment Why would an RSA library tell me that the public key must be at least 512 bits in size?
Obviously, you can't use a 512 bit RSA key for generating sha512withRSAEncryption signatures. The restriction on key size might have to with more than just best practices.
Sep
15
answered Feasibility of finding public key when private key is known
Sep
10
awarded  Popular Question
Sep
3
comment Are SSL/TLS used for maintaining data confidentiality?
Please read the answer again. Data as a whole might not necessarily be confidential, just because it is encrypted. The hash functions are used for the message authentication codes and (in TLS 1.2 and up) for the PRF that is used e.g. for deriving bulk encryption keys. The description in the other answer crypto.stackexchange.com/a/18936/1564 is generally correct in this respect.
Sep
3
answered Are SSL/TLS used for maintaining data confidentiality?
Aug
25
reviewed Approve suggested edit on One Way function and Merkle Damgård
Aug
22
reviewed Close Variants of AES?
Aug
22
reviewed Leave Open Which causes longer “break” time (in general)?
Aug
22
comment Why does DES use exactly 16 rounds?
@fgrieu You are probably correct.
Aug
21
awarded  Custodian
Aug
12
comment Deterministic Rand function for Winternitz One Time Signatures
I need (at least) 256 bit outputs because the Winternitz OWF has a 256 bit output. I need (at least) a 256 bit key, because the risk of collisions in the leaf keys must nut exceed the risk of collisions in the message digest function. I need a 256 bit seed because the number of leafs is $2^{250}$ and the total number of independent leaf keys is $2^{256}$.
Aug
11
comment SHACAL in SHA-256
Yes, SHACAL-2 was e.g. selected as part of the NESSIE portfolio. However, it should be noted that some standard modes of operation don't have a 256-bit equivalent, such as GCM.
Aug
10
answered SHACAL in SHA-256
Aug
9
comment Discovering private exponent from public key
Correction: The order $q$ of $g$ is the least positive integer such that $1 = g^q \bmod N$. You are correct that an element $g$ is a generator of the multiplicative group if its order is $q = N-1$. Also please note that $N = 251$ isn't a safe prime, since $(N-1)/2 = 125$ isn't a prime.
Aug
9
comment Discovering private exponent from public key
The parameter $n$ in my answer is an arbitrary attack parameter that might be any value between $0$ and $128$.