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bio website github.com/CodesInChaos
location Frankfurt, Germany
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visits member for 3 years, 4 months
seen 37 mins ago

Jan
7
comment Why use CBC-MAC? Why not just apply hash function on the whole message?
1) Hash != MAC 2) Most hash functions divide the message into blocks internally 3) MACs don't need to be collision resistant, and CBC-MAC isn't. 4) I don't get your questions
Jan
7
comment is there an algorithm to encrypt all the datatypes?
Typical encryption algorithms operate on sequences of bytes. All of those data-types can be serialized to bytes, so the all can be encrypted with any common algorithm. The ciphertext won't conform to typical video/audio/... formats. It's just a bunch of bytes.
Jan
6
comment Is Curve25519-java secure?
That Ed25519 implementation is glacially slow. Both the Curve25519-java implementation and the ed25519-java you linked aren't constant time, and thus potentially open to timing attacks (probably not a practical issue in this context).
Jan
6
comment Is Curve25519-java secure?
Curve25519-java supports signing, but that wasn't in the original code and thus hasn't seen much review. It's also missing the other Ed25519 goodies, such as deterministic signatures, batch verification, or the faster fixed base multiplication.
Jan
6
comment Is Curve25519-java secure?
As far as we know, Curve25519 itself is secure. But Curve25519 as specified by Bernstein only supports key-exchange, not signing. For signing I recommend using the related Ed25519 instead.
Jan
6
revised In this example, which is a premaster secret, and which is a master secret?
[Edit removed during grace period]
Jan
4
comment Deterministically combine more than one source of entropy
can't you just hash them and map the hash to 0..1?
Jan
4
revised Can we ensure the security of a crypto-algorithm and -implementaton against acoustic cryptanalysis?
added 12 characters in body
Jan
4
comment Can a salt for a password hash be public?
Salts aren't there to prevent pre-computation. They prevent multi target attacks. Rainbow tables are one particular example of multi target attacks, and a rather useless one.
Jan
3
revised Where does the $\varphi(n)$ part of RSA come from?
added 3 characters in body
Jan
3
comment Usability of padding scheme in blinded RSA signature?
Padding adds a redundancy of a particular form. A random value almost certainly doesn't have that form and is rejected.
Dec
26
reviewed Approve suggested edit on accumulators tag wiki excerpt
Dec
26
reviewed Approve suggested edit on key-schedule tag wiki
Dec
26
reviewed Approve suggested edit on key-schedule tag wiki excerpt
Dec
26
reviewed Edit suggested edit on quadratic-residuosity tag wiki excerpt
Dec
26
revised quadratic-residuosity wiki excerpt
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Dec
26
reviewed Edit suggested edit on quadratic-residuosity tag wiki
Dec
26
revised quadratic-residuosity wiki description
deleted 1 characters in body
Dec
26
reviewed Approve suggested edit on accumulators tag wiki
Dec
26
comment Security Level Estimate when Cascading/Compositing Ciphers?
Nowadays the reason for cascading is guarding against cryptoanalytic advances against one primitive ensuring that the whole system is as secure as the strongest primitive. It's not a good way to raise the security level.