I have an ID-Secret scheme and I'd like to hear if there are any vulnerabilities present. Party 1 and Party 2 hold some credentials, an ID and a Secret. Party 1 Creates this message: ...
Can someone tell me which mode out of ECB and CBC is better, and how to decide which mode to use? Are there any other modes which are better? Edit: This question was asked long back when I was ...
Most of the time, when some data must be encrypted, it must also be protected with a MAC, because encryption protects only against passive attackers. There are some nifty encryption modes which ...
Is it possible to create an asymmetric cryptosystem where the private keys are not easily verifiable as such?
Plaintext that consists of an RSA key is easily recognizable as such, because it satisfies certain mathematical properties, in particular (See the answer for Why can an encrypted private key be brute ...
Is it possible to construct an (asymmetric) encryption scheme from a signature scheme? If the signature scheme is deterministic and allows existential forgery (e.g. RSA), then the answer is yes ...
Is it possible to identify the encryption method, or at least rule out some of them, by looking at the encrypted text? For example, if you have 3 encrypted strings where the first 10 characters are ...
Does anyone know of any sites where intermediate values of multiple crypto algorithms (not just the famous ones), including hashes, can be found? I don't just mean intermediate values of encrypting. ...
The Rijndael S-Box design generates a permutation cycle of type $2+27+59+81+87$. What effect would replacing that permutation with a cycle of type $256$ have on the security of AES?
I think I once faced the recommendation, that the initialization vector should always be random and never be used twice with the same key. How serious is this weakness? Also, is AES less effected ...
A few years ago I devised a symmetric-key system that worked like so: ...
I was attending a database encryption session at a developers conference. The presenter (who was a published author on the subject) said that MS SQL Server did not support salted hashes in the ...
As I understand it, SSL involved the use of a public-private key pair. How does this enable two-way communication? Suppose I have some server with which I wish to communicate securely. I connect to ...
AES has several different variants: AES-128 AES-192 AES-256 But why would someone prefer use one over another?
It seems like the S-boxes in DES have essentially random values. How were these chosen?
RSA is not designed to be used on long blocks of plaintext like a block cipher, but I need to use it to send a large message. How can I do this?
Does there exist any cryptographic algorithm which encrypts data in such a way that it can only be decrypted after a certain period of time? The only idea that I can think of, is something like this: ...