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I like crypto. Need I say more?


9h
comment How can an email sender include his PGP key, so I can answer with an encrypted mail?
Migrating this to Security.SE as it is a better fit. Thanks for visiting out site though.
15h
comment How to make a document truly read only
And remember, this is a cryptography site so our solutions will definitely be geared towards cryptography. There could be non-cryptographic answers to the question.
15h
comment How to make a document truly read only
Answer is, you probably can't. Anyways, you need to define a threat model. What do you consider a breach of "read only"? If someone memorizes the document and types it out in a new word processor document? Printing? Etc. If you can formally define what it means to be read-only, we may be able to help.
17h
comment How Proof all Subgroup point of prime order elliptic curve have prime order [#G=#E]?
Given Lagrange's theorem (which will be in any decent textbook on number theory), the proof is straight forward.
19h
comment How Proof all Subgroup point of prime order elliptic curve have prime order [#G=#E]?
Actually, there is one point for which this will not hold.
Aug
27
comment What's the point of a Meet In The Middle attack using i.e. double AES with throw-away keys?
First off, a meet in the middle attack on AES is not even computationally feasible, so an attacker wouldn't use it period.
Aug
26
comment why should one use lattice-based systems in travel documents in post- quantum computers era?
What research have you done?
Aug
26
comment How to distribute symmetric key between $n$ entities?
Shamir secret sharing?
Aug
22
comment Is it secure to derive an AES key from a MAC?
@HannoBinder your idea is valid, but I don't necessarily think it is simpler.
Aug
22
comment Is it secure to derive an AES key from a MAC?
@Augusto are you the OP? They seem reasonable to me. In any usable system there is going to be a point where security breaks.
Aug
22
comment Is it secure to derive an AES key from a MAC?
Having never worked with HSM's, is there any sort of authorization with them? I.e., to prove that you are allowed to generate keys? An attacker stealing the database who also has access to the server with the HSM, could issue the random numbers to the HSM and get back the decryption keys.
Aug
22
comment How does a chosen plaintext attack on RSA work?
Link only answers are not typically well received here. While the paper is a very good one, you should consider expanding by talking about what information the paper presents that is specifically related to the question.
Aug
15
comment Multiparty Computation with ORAM
To quote the paper DrLecter mentions "For simplicity, we focus only on the two-party (client/server) setting in the semi-honest model but it is clear that our definitions can be extended to the multi-party case with malicious adversaries." Having not read the paper, I can't tell you why it is clear. Perhaps it would be better for you to post why it isn't clear. What issues do you see with directly applying their work to the multi-party case?
Aug
15
comment Chosen plaintext attack on textbook RSA decryption
When you say "I must generate a random $n$ from a range of $n-1$ values" do you mean "I must generate a random $r$ from a range of $n-1$ values"?
Aug
14
comment Chosen plaintext attack on textbook RSA decryption
Can you update your question using MathJax? It will make the equations much more readable. Also, what have you tried? Where are you stuck in solving it yourself?
Aug
12
comment Multiparty Computation with ORAM
What do you mean by "better" when comparing with secret sharing?
Aug
10
comment $(k, n)$ threshold secret sharing to $(k+k', n + n')$ without reissuing all shares
How trustworthy are the parties who are given the shares?
Aug
10
comment $(k, n)$ threshold secret sharing to $(k+k', n + n')$ without reissuing all shares
Do you have an adversary model in mind?
Aug
5
comment How many degrees of freedom up my sleeve?
This might be hard to answer unless you can come up with a good measure for how suspicious an algorithm is.
Aug
5
comment How to only encrypt a subset of the plaintext
Is there one continuous subset or many disjointed subsets? Do you require that the output (of plaintext and ciphertext) be the same length as the input plaintext? Do you want the ciphertext to be in-line with the plaintext?