Linked Questions

0
votes
5answers
10k views

Why can't you decrypt an encrypted message with just the public key? [duplicate]

How does asymmetric crypto work? For example, if you use PGP in emails, you generate a private key that is known only to you and a public key, which is available to everyone. Is there a simple way ...
1
vote
1answer
199 views

How can public key not reverse encryption if the algorithm is known? [duplicate]

I've been reading about WhatsApp getting "end-to-end" encryption, and when reading about it, I've notice something. If I want to send a message from cell $A$ to cell $B$, since there's a public key, ...
0
votes
1answer
170 views

Public key encryption [duplicate]

I am not getting whole idea behind Public Key Encryption technique. As according to fact, public key encryption method uses two keys a public key known to everyone private key known only to recipient ...
67
votes
5answers
28k views

How are primes generated for RSA?

As I understand it, the RSA algorithm is based on finding two large primes (p and q) and multiplying them. The security aspect is based on the fact that it's difficult to factor it back into p and q. ...
16
votes
4answers
17k views

What is the relation between RSA & Fermat's little theorem?

I came across this while refreshing my cryptography brain cells. From the RSA algorithm I understand that it somehow depends on the fact that, given a large number (A) it is computationally ...
9
votes
3answers
5k views

What place do prime numbers have in cryptography?

My understanding of hashing and encryption is rather limited. I certainly do not understand the mathematical formulas at play in these algorithms. With that said, what part do prime numbers play in ...
3
votes
2answers
2k views

How can a message encrypted with the public key be decrypted with the private key?

I've been reading about encryption and have a basic understanding of the concept. What I don't understand, however, is how a calculation with one key can result in a number that, through calculation ...
1
vote
1answer
372 views

Public Key encryption /Assymetric encryption

For a start, I 've got a question regarding the Public key encryption. I know the public key encryption overcomes the Key distribution issue with the symmetric encryption and that in the case of ...
-2
votes
1answer
399 views

Is there an encryption that is only reversible with a key?

I'm thinking about man-in-the-middle attacks during a website login, and started wondering about reversible encryption. What I'm imagining is an encryption that takes input ...
1
vote
1answer
133 views

Private key can't be traced (GPG)?

I am very new to cryptography. I was reading about GPG/PGP Basics when a doubt arose: As per my understanding, everyone knows the algorithm (from GPG) with which I generated my key pair. If I show my ...