Questions tagged [rsa]

An asymmetric (e.g. public-key) cryptosystem, based on modular exponentiation with big exponents and modulus. RSA can be used both for signature and encryption with proper paddings.

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What is the difference between probabilistic and deterministic prime-factor recovery function in NIST 800-56B?

In the previous standard, the deterministic was not included. It is already in the current standard. What is the reason for this? Can I use both function?
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Why is it necessary a prime factor recovery for a RSA Key-Pair Validation (in case of fix public exponens)?

In NIST 800-56B publishing, this is done with the $(p, q) = RecoverPrimeFactors (n, e, d)$ function. I don't understand why is necessary if $p$ and $q$ are known during in generation. In my opinion, ...
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How many points in RSA, such that $m^e = m \bmod n$

For every RSA-cryptosystem, there exist some messages $m$, for which it holds that $m^e \equiv m \pmod n$ As to the question, how many such messages exist, this question has already been asked and ...
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RSA public key identification

Consider a multi party system where public keys of all receivers are known. Server wants to send message to one of them using (textbook?) RSA. Adversary is given ciphertext and even Message to be send,...
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Does blinding protect again fault injection attack against RSA with CRT

I know that blinding can be used as a countermeasure against side-channel timing attacks on RSA-CRT: RSA Timing Attack and Prevention through blinding My question is: can blinding also be used as a ...
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RSA with Carmichael number

I've to prove that RSA still works with a public key $(e,pq)$ where p is a prime and q is a Carmichael number such that $q<p$ and $\gcd(e,(p-1)(q-1))=1$ I know how RSA works wiht $p,q$ primes but ...
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How can a recipient recognize which encrypted messages are intended for them?

Let's say there's a decentralized email service where parties' public keys are known. A sender sends a message to a recipient by encrypting via RSA with the recipient's public key and posting the ...
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Why is $\phi(N) = (p^2 -1) (q^2 - 1)$ here?

I was reading a paper on attacks on RSA variants, and the paper equates $\phi(N) = (p^2-1)(q^2-1)$. Before, I have always seen $\phi(N) = (p-1)(q-1)$ and don't understand why it is different here. I ...
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RSA message encryption question

I'm very new to cryptography, I wanted to know what exactly do I have to do to encrypt a three-letter message using RSA? for example if I wanted to encrypt this message $M= \text{HCP}, p=11 q=13$. Do ...
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Faster alternatives to RSA trapdoor permutation

We're working on web3.0 decentralized internet, a big part of which is a decentralized file storage system where clients upload files to storage providers and pay them for the services. Storage ...
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is this useful to help break RSA?

So, I'm kinda newbie in this cryptography stuff, I just like to understand complex things.A couple of months ago I was learning and I maybe found a pattern in prime numbers and their multiplications, ...
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What if the bitlength of the value evaluated in Barrett reduction is greater than 2k the modulus?

For $c\equiv a \pmod n$, in Barrett Reduction, $\mu = \lfloor{\frac{2^{2k}}{n} \rfloor}$ is precomputed, where $k = \lceil{\log_2{n}} \rceil$ and the bitlength of $a$ is assumed to be less than $2k$. ...