Linked Questions

19
votes
2answers
8k views

Which attacks are possible against raw/textbook RSA?

The PKCS#1 standard defines multiple padding schemes for signature generation/verification (EMSA-PSS and EMSA-PKCS1-v1_5), and encryption/decryption (EME-OAEP and the less safe EME-PKCS1-v1_5). ...
2
votes
2answers
4k views

RSA PCKS1 v2.1 RSAES-OAEP algorithm

Using RSA public key (n,e) the encryption of a message is c= (m^e) mod n and the corresponding message is decrypted as ...
2
votes
3answers
885 views

Input limitations on the RC6 cipher

RSA has limitation in input size for encryption and decryption. Can RC6 be used for encryption and decryption of files larger than 5 MB? Is there any limitation for input size? Is RC6 safe for using ...
0
votes
1answer
593 views

RSA encryption/decryption process is not working correctly

I'm trying to apply the RSA cryptosystem to encrypt a byte M=72, using predefined modulus n, public key exponent ...
0
votes
1answer
191 views

RSA How to select a value K such that $e d = 1 + k \varphi(N)$ holds

I am learning RSA cryptography. The part I am stuck on is understanding how k and the public exponent $e$ is selected. Given the formulas; Decrypting: $c^d \bmod N = (m^e)^d \bmod N$ Which is equal ...
27
votes
5answers
45k views

Why is padding used for RSA encryption given that it is not a block cipher?

In AES we use some padded bytes at end of message to fit 128/256 byte blocks. But as RSA is not a block cipher why is padding used? Can the message size be any byte length (is the encrypting agent ...
3
votes
2answers
201 views

Help with RSA step

There's one thing in RSA that haunts me. In books there's just a statement, that $$ed \equiv 1 \bmod \varphi(n)$$ is taken from Euler's function somehow. And than we use it to get $$m^{ed} \equiv ...
5
votes
4answers
7k views

Is it safer to encrypt twice with RSA?

I wonder if it's safer to encrypt a plain text with RSA twice than it is to encrypt it just once. It should make a big difference if you assume that the two private keys are different, and that the ...
24
votes
2answers
29k views

When to use RSA and when ElGamal asymmetric encryption

If i am not wrong in cryptography there are 2 basic cryptographic schemes for public key cryptography. RSA encryption whose security is based on the infeasibility of solving the factoring of big ...
-3
votes
1answer
3k views

Why plain RSA encryption does not achieve CPA-security?

Why plain RSA encryption does not achieve CPA-security?
0
votes
1answer
538 views

I think I'm trying to find the C in an RSA cipher to find the key for an aes_128_ecb cipher, can anyone tell me if I'm on the right track?

And if I am on the right track, how do I reach the solution from here? I'm doing a CS game and I've hit a wall (I'm a rank beginner when it comes to encryption) on the encryption portion. I've been ...
3
votes
2answers
437 views

Does order matter for RSA when used multiple times?

I actually have no idea how RSA works, but I currently (think that I) know Public and private keys are mathematically doing their opposites Therefore, the order in which they are applied doesn't ...
-3
votes
1answer
424 views

How does the math part of RSA work? [duplicate]

I understand the theoretical part of RSA (the concept of public and private keys), but I don't understand the mathematical part. Can anyone please explain it to me in simple terms? Thanks.
1
vote
0answers
78 views

How secure is 'Plain Old RSA' [duplicate]

Let's say I use RSA encryption, it's 2048 bits and I use a simple character padding scheme, every character is turned into a 3 digit number and strung together, then encrypted. Saying that no message ...
5
votes
1answer
3k views

Are there comprehensive alternatives to RSA?

If we wished to, is there a comprehensive alternative to RSA? I say comprehensive as I wonder if there is one which does both encryption and digital signature like RSA? If not, simply what ...

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