Linked Questions

0
votes
2answers
188 views

How to sign with RSA safely?

what should I do to make my RSA signatures secure? If "plaintext RSA" is not secure, is there some sort of "RSA on steroids" I am not aware of? Could anybody tell me what is it? I read a Wikipedia ...
10
votes
1answer
357 views

Could this “symmetric RSA” scheme provide key compromise resistant communications?

This question, and fkraiem's answer to it, made me wonder about the security and practicality of using "symmetric RSA" to provide a partially compromise-resistant secure channel. Specifically, assume ...
6
votes
1answer
4k views

ECDH or RSA more secure for symmetric key wrapping?

Suppose a message is encrypted with a symmetric block cipher with a random key. RSA is often used to wrap the symmetric key using the recipient's public key. In this case, the size of the message is ...
3
votes
1answer
2k views

Why is RSA-2048 max input 245 bytes?

I can see that the message (after padding) should not be 256 bytes because it might be bigger than the modulus of RSA. So I think that the message should be 255 bytes, but I saw posts that says the ...
2
votes
1answer
686 views

What use is the signature without the message under RSA?

Using RSA for signing & verification, is there a way to take a valid signature for an unknown message, and for someone else to generate a valid signature using a different key against the valid ...
1
vote
1answer
3k views

Strength of RSA with OAEP

In our current system we use an encryption solution based on RSA with OAEP padding. Key size is optional but default 2048. What is the general strength of RSA with OAEP? Are there know attacks that ...
1
vote
1answer
93 views

special public keys and modulo n

I just picked up cryptography and have some questions on RSA cryptosystem: Say there are two public keys (n, e1), (n, e2), e1 is coprime to e2. They share the same n. Is it possible to find the ...
1
vote
1answer
2k views

OpenSSL RSA same plaintext but different ciphertext

how OpenSSL RSA work ? I generate public (n,e) and private key (n,d) then I encypted a file by : ...
0
votes
1answer
89 views

Asymmetric sign in public enviroment

I have RTS game, where all players run game and server just relays messages. Game can generate and store text file on player pc. I want to allow some players to be moderators, so I need to sign or ...
0
votes
1answer
190 views

Possible to know who is the owner of a message encrypted with RSA public key

Given the scenario in which I want to send 10 messages either to Stalio or Olio. I encrypt these messages with their respective public keys using textbook RSA, before sending the messages to their ...
-1
votes
1answer
752 views

RSA : if my key and message are too large , how to do?

I want to send a message consisting of a string of number (e.g: 124124134235235) Then, p:125243 q:56454547 e: 2659043 d: 5261378624675 However, it will be too large...so, is there any solution to ...
-3
votes
1answer
3k views

Why plain RSA encryption does not achieve CPA-security?

Why plain RSA encryption does not achieve CPA-security?
3
votes
0answers
67 views

What type of attacks are practical for this situation?

Here is the details: I found a web api while pentesting for a company which I cannot disclose and while doing so I found a API which signs a request of the users choice, but it adds a tag to the top ...
1
vote
0answers
93 views

RSA algorithm assignment [duplicate]

Alice wants to share a symmetric key with Bob. She encrypts the small (64-bit) secret key $K$ with Bob’s public RSA key $(n,e)$ by padding it with zeroes to 2048 bits (the length of n) and computing $$...
1
vote
0answers
92 views

Is signing a message just encrypting it with private key? [duplicate]

I have a simple question, When I sign a message (in RSA) does the program encrypt the text with my private key? Because I can decrypt it with my public key. Yes or no. Is signing a message just ...

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