Public key cryptography describes all cryptographic algorithms which have a pair of keys, one key that performs encryption and one key that performs decryption. One of these keys is made available publicly, allowing anyone to send messages that only the holder of the private key can read. You should ...
7
votes
3answers
376 views
Asymmetric cryptographic algorithms that are not based on integer factorization and discrete logarithm
In the computer security class (in which cryptography is a big chapter) that I took, I remembered the professor said about current asymmetric cryptography algorithms are based on integer factorization ...
6
votes
1answer
1k views
How do other, non-RSA algorithms, compare to the PKCS #1 standard?
Arguably the PKCS suite of standards have a profit-oriented bias as they are promoted by RSA and promote their algorithms over others in the form of RFCs and other means.
I'm considering the ...
3
votes
1answer
133 views
When is an asymmetric scheme considered broken?
Does the following quote imply that valid encrypted data can be created and decrypted by someone other than the owner of a private key:
An asymmetric encryption scheme is considered to be broken ...
3
votes
1answer
136 views
Signature scheme with two private keys, neither derivable from the other
Is there any scheme, ideally one widely used or at least widely available, where you can treat both the signing and verifying keys as secret?
Basically, the functionality I'm looking for is this:
...
2
votes
1answer
117 views
A set of key pairs and one hash to secure them
I have a simple problem: I have a set of users' ECDSA key pairs, and say I want to encrypt them with a simple algorithm. I have access to one variable that uniquely identifies the user, so I hash it ...
3
votes
2answers
234 views
If Bob steals Alice's private key, how exactly would he read her encrypted documents?
So Bob grabs Alice's secret key when she isn't looking and her encrypted files, doesn't he need to know her passphrase to read her files?
What I am reading is that no he does not need it but as far ...
8
votes
3answers
241 views
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 ...
5
votes
2answers
868 views
Why can't Diffie-Hellman be used for signing?
I understand that signing is often a case of hashing data and then encrypting the hash with the private key. What properties keep Diffie-Hellman from being useful for this?
4
votes
3answers
265 views
Preventing message replay with RSA
I am using RSA to encrypt some data but I would like to eliminate the possibility of message replay. By message replay I mean sending a valid message multiple times to the original recipient. It is ...
3
votes
2answers
526 views
Can a computationally unbounded adversary break any public-key encryption scheme?
Assume there is a public-key encryption scheme $(KeyGen, Enc, Dec)$ with perfect correctness (i.e., for all messages M and valid key-pairs (PK,SK), we have $Dec_{SK}(Enc_{PK}(M))=M$).
Will there ...
13
votes
4answers
4k views
Basic explanation of Elliptic Curve Cryptography?
I have been studying Elliptic Curve Cryptography as part of a course based on the book Cryptography and Network Security. The text for provides an excellent theoretical definition of the algorithm but ...
2
votes
1answer
354 views
Digital Signature Algorithm signature creation
I was studying DSS from "Cryptography and Network Security" by William Stallings. What puzzled me was the DSS approach figure described in the text. It says it uses Public and Private Keys for ...
11
votes
3answers
3k views
Why is public-key encryption so much less efficient than secret-key encryption?
I'm currently reading Cryptography Engineering. After giving a high level explanation of the difference between secret-key encryption and public-key encryption, the book says:
So why do we bother ...
9
votes
5answers
2k views
Types of Cryptography for a 4-8 bit microcontroller
This is more of a research question.
I was wondering what types of crypto algorithms would work best on a small 4-8 bit micro controller. I recently read a paper called Security Considerations for ...
15
votes
5answers
5k views
How does asymmetric encryption work?
I've always been interested in encryption but I have never found a good explanation (beginners explanation) of how encryption with public key and decryption with private key works.
How does it ...
1
vote
3answers
360 views
Is public-key cryptography the only option in this scenario?
Two parties: a client and a server are to a agree on a symmetric key. Both the client and the server are aware of a master password. The way this is currently done ...
6
votes
3answers
162 views
Number of intersections of two sets
Suppose both I and my friend have a set of integer numbers. We want to know the number of common elements in our two sets but without knowing elements of the sets of each other. So I don't want my ...
8
votes
2answers
566 views
Are any of the major asymmetric ciphers distinguishable (EG, RSA, ECC) ?
Related to this question.
Given ciphertexts generated by any of the major asymmetric ciphers (RSA, ElGamal, ECC, etc..) can these ciphertexts be distinguished from random noise? Justify why, why ...
