2
votes
4answers
139 views

What is the difference between authenticate a document and sign a document?

Is it a kind of same? Authenticate means it is from sender. Also sign is done by the sender. Can someone please give a clear view about their relationship?
0
votes
2answers
193 views

Can a salt for a password hash be public?

For my understanding salts in password hashes are used to prevent the precompuation of plaintext$\to$hashvalues (rainbow tables). I know from different threads, it is not necessary to keep the salt ...
2
votes
1answer
81 views

Proof of shared secret through key derivation

Alice gives a random key $K$ (e.g. 32 bytes long) to Bob through a secure channel. Bob want to prove to Alice through an unsecured channel that he knows the key. Is it secure for Bob to send ...
2
votes
1answer
82 views

With Encrypt-then-MAC, and flexible protocols, do I need to authenticate the authentication?

Sorry, the question is not easy to state (or wasn't for me, anyhow). So I'm writing a very flexible format for security. It allows for full choice of cipher, key size, and so on, along with key ...
3
votes
1answer
102 views

What security differences are there between E(p',“well-known-plaintext”) vs. hash(p') where p'=KDF(p)

I am using a KDF to derive a key, p' from a password p. I would like to know if the password is correct before using the derived ...
2
votes
2answers
308 views

What are the potential security impacts of using CRAM-MD5 for Emails, when not using an SSL connection?

Background: My current server-provider tells me it's no problem to store the passwords in plain-text in the database, saying he has to do so because they use CRAM-MD5 for email authentication. But ...
2
votes
1answer
155 views

How to use salt if I am sending hashed password?

If have application that is sending username and hashed password to server for authentication, how would I use salt for this scenario ?
11
votes
1answer
4k views

What are the differences between a digital signature, a MAC and a hash?

A message may be accompanied with a digital signature, a MAC or a message hash, as a proof of some kind. Which assurances does each primitive provide to the recipient? What kind of keys are needed?
2
votes
1answer
243 views

Is there another resource for Carter-Wegman-style message authentication?

I'm wondering if there are other resources that cover Carter-Wegman style message authentication, besides the sources themselves. Is there an online text or a book that covers their ideas? I'd ...
4
votes
4answers
854 views

How can I validate a hashed password if all I have is another hash?

The Scenario I have a client-side web application that bounces requests against a server-side API. For the sake of simplicity, every request must pass a username and password. This is similar to ...
4
votes
2answers
500 views

How did LinkedIn “salt” all their passwords?

First, just to make sure I understand "salting" correctly: You randomly generate a string to append to the password before hashing it, so as to increase its length and make precomputed tables much ...
1
vote
2answers
313 views

How to generate successive stream-cipher keys?

I've identified a weakness in a distributed simulation system I'm looking at, and I'm looking for some advice on how to fix it. Clients initially negotiate an authentication token with a login server ...
2
votes
1answer
436 views

Hash or encryption function for challenge-response protocol?

Say I have an authentication protocol where the shared secret is never transmitted. The server passes a challenge to the client and the client calculates a response using an algorithm where the ...
5
votes
1answer
636 views

What is the proper way to use a client nonce?

I've implemented an API for one of my clients, it relies on nonces and a shared secret. The structure: Client's Site (CS) requests nonce from My App (MA), posting their username MA verifies the ...