Questions tagged [key-generation]

Key generation is the process of generating keys for cryptographic purposes.

Filter by
Sorted by
Tagged with
5 votes
2 answers
2k views

Where do key generation algorithms take the randomness from?

I was just wondering, because in many encryption tools like Veracrypt or GnuPG you have to generate pseudo randomness with your mouse movement. So, where do automatically generated keys take that ...
user avatar
1 vote
1 answer
1k views

Find inverse in RSA

I've been reading on RSA for a while but there's something I still can't understand. When generating the key: once you find n = pq and φ(n), you choose a number d coprime with φ(n) and then you need ...
user avatar
  • 135
1 vote
3 answers
335 views

How to combine pepper in random string generation

I am writing a key generator program. Indeed it generates a key in the form of a random text string (not binary), with its characters chosen randomly from a set of defined characters, with a ...
user avatar
  • 447
2 votes
0 answers
271 views

Rijndael - is there some difference in resistance between counter in generator input and in IV?

I am thinking about Rijndael implementation in order to store tokens (cannot be hashed) - one token for one user. And finally I get stuck with key/IV generation problem :( The questions are: 1) Is ...
user avatar
  • 121
1 vote
0 answers
498 views

Time taken to break cryptographic key

Assume it takes 512 clock cycles to check if a 64 cryptographic bit key is correct. Given a 64 bit plain text and its ciphertext, how long does it take to check all keys using a single core of a 4 GHz ...
user avatar
0 votes
1 answer
130 views

Are there any downsides to key stretching an already high quality entropic key?

For example, if we grab 50 bytes from a high quality source and run them through a key stretching function like Argon2 and have it generate a 32 byte secret for AES. Is there any downside to this? Do ...
user avatar
  • 45
3 votes
1 answer
120 views

Is there an asymmetric scheme where keys form a graph and a message can only be decrypted across a certain degree of separation?

Consider a network of trust, where each user u specifies some other set of users whom u "trusts". This forms a graph with users ...
user avatar
  • 131
1 vote
1 answer
285 views

securing the keystore

When generating a public-private key pair you have the option to secure the keystore with a password. where is that password stored, is it a hashed version that is stored and if that is so which ...
user avatar
  • 155
3 votes
1 answer
404 views

Why isn't ElGamal a symmetric-key scheme?

I was asked about this question by a friend. He considers that Alice and Bob share a secret key s=g^(xy). So why isn't it considered a symmentric-key scheme? ...
user avatar
1 vote
1 answer
480 views

CP-ABE Key generation random parameters

In the key generation algorithm of cp-abe there are attributes: $x_1, x_2,...x_n \in \{0,1\}^*$ $r, r_{x_1}, r_{x_2},...r_{x_n} \xleftarrow{R} Z_p$ are chosen randomly to generate the private key $...
user avatar
1 vote
2 answers
674 views

Guidelines for cryptographic key generation

I was wondering whether you know can point me to some general (basic) principles/guidelines one should follow for generating cryptographic keys? I have looked at NIST 800-133, but was hoping for some ...
user avatar
  • 39
2 votes
2 answers
386 views

Generating DH key with specific bit-length

In PKCS#3 the generation for DH secrets mandates to generate them with a minimum size if length is specified: The central authority may optionally select an integer $\ell$, the private-value length ...
user avatar
  • 636
1 vote
1 answer
121 views

RSA key generation gives d=1

I was reviewing RSA by hand. I picked 53 and 59 as my primes. For e I picked 5. When I solved for d using extended euclid, I got 1 which obviously doesn't decrypt anything. I checked my answers online ...
user avatar
5 votes
1 answer
3k views

What are the differences between X9.31 RSA operation and PKCS#1 RSA operation?

NIST and other - mainly older - standards often don't just mention PKCS#1 RSA algorithms but also X9.31 RSA algorithms. What are the differences between X9.31 and PKCS#1 (v2.1) with regards to key ...
user avatar
  • 85.8k
2 votes
1 answer
174 views

Finding $f^{-1}$ in the YASHE keygen algorithm

In the YASHE (Yet Another Somewhat Homomorphic Encryption) algorithm, the beggining of the key generation step specifies: Sample $\ f',g ← χ_{key}$ and let $\ f = [tf' + 1]_q$. If $\ f$ is not ...
user avatar
2 votes
2 answers
143 views

How do I pick variable length passwords uniformly at random?

How do I pick passwords uniformly at random when given a min and max length? It seems that if I first pick a random length, then choose random characters, this procedure will choose shorter length ...
user avatar
12 votes
2 answers
3k views

Should RSA primes p and q differ in length by "a few digits"?

When generating RSA keys in the original RSA paper it is stated: to gain additional protection against sophisticated factoring algorithms, p and q should differ in length by a few digits Why is ...
user avatar
56 votes
3 answers
2k views

Do these new insights into prime numbers affect encryption security?

Quanta Magazine reports: Two mathematicians have uncovered a simple, previously unnoticed property of prime numbers [...]. Prime numbers, it seems, have decided preferences about the final digits of ...
user avatar
  • 503
1 vote
1 answer
257 views

Building multiple keys from the same input using a KDF [duplicate]

Let's say I have a single secret with high entropy, S, for the entire application. I want to generate keys K1, K2 for 2 ...
user avatar
2 votes
2 answers
3k views

Obtaining Diffie-Hellman generator

In the Wikipedia article on Diffie-Hellman, the algorithm calls for a large prime modulus, $p$, and a generator, $g$, which is a primitive root of $p$. As far as my knowledge of number theory goes, ...
user avatar
2 votes
1 answer
98 views

Which algorithm would be ideal for ephermal key generation followed by DH key exchange?

Bob and Alice, both generate a temporary public key pair each using X algorithm on their individual PC. After being authenticated by a third party, they use the DHE to come to get a common symmetric ...
user avatar
0 votes
1 answer
406 views

Why is it that in DSA, the order of the subgroup, $q$, is chosen such that it divides $p - 1$?

Consider the DSA key generation: A large prime $p$ is chosen; A smaller modulus $q$ is chosen such that $p - 1$ is a multiple of $q$; A generator $g$ s.t. $\operatorname{ord}_p(g) = q$ is chosen. My ...
user avatar
  • 192
4 votes
1 answer
621 views

How to generate a bilinear group of prime order p for key generation

I am trying to implement an IEEE Paper In Cryptography. I read many reference regarding an RSA key generation. But i am confused with above statement. Please someone explain me What it says with ...
user avatar
11 votes
3 answers
8k views

Are all possible EC private keys valid?

I usually generate a key pair using OpenSSL or Bouncy Castle. I'm using curve secp256k1. The 256bit private keys look fairly random. Do all values of "private ...
user avatar
6 votes
1 answer
15k views

Is there a correct way to generate a symmetric key?

Looking in some cryptographic algorithms, I've realized that: The way the plain text is encrypted/decrypted is always specified, but what about the key? Every paper I've seen describing the algorithm ...
user avatar
  • 163
3 votes
1 answer
557 views

Number generation for Fujisaki-Okamoto commitment scheme parameters

I need to implement the Fujisaki-Okamoto commitment scheme for a project such that I can demonstrate performance of various zero-knowledge proofs in relation to one another, for example Boudot's "...
user avatar
5 votes
1 answer
216 views

Parameter choice Supersingular Isogeny DH

In “Towards quantum-resistant cryptosystems from supersingular elliptic curve isogenies” by DeFeo, Jao and Plut (PDF), the public parameters are defined as: Supersingular curve $E$, and bases $P, Q$ ...
user avatar
  • 482
2 votes
0 answers
41 views

Are there UFDs where the factorization problem is difficult but finding irreducibles is cheap?

Factorization of integers is hard, but finding irreducibles is expensive. Is there a ring where factorization is assumed hard but finding irreducibles is much cheaper than over $\Bbb Z$? It could ...
user avatar
  • 1,189
1 vote
1 answer
367 views

How to determine the exponent when using RSA

Can someone please explain to me how, when using RSA, to determine the exponent to be used in encryption and decryption? I have attempted a worked example on using RSA (shown below) but I can't ever ...
user avatar
  • 11
4 votes
1 answer
1k views

Can I use an ECDH Shared Secret from the same Private / Public Key Pair?

I'd like to know if using the ECDH shared secret of a static EC Private Key with it's own corresponding static EC Public Key causes a problem / weakness. (edit) not asking if it's ok to re-use the ...
user avatar
  • 53
2 votes
4 answers
717 views

How is an epsilon of 1/1000 non-negligible?

Lately I've been studying cryptography and in the current course I'm taking we're reviewing statistical tests and how they can be used to determine if a pseudo-random generator is secure or not. ...
user avatar
2 votes
0 answers
415 views

Proper way to generate symmetric keys [duplicate]

I'm trying to educate my self in key management, how to store them, how to generate them, how to use them properly. I've been trying to find how you would generate a key for symmetric encryption (say ...
user avatar
  • 936
2 votes
1 answer
124 views

Key derivation design to avoid key leaks

I have the first function that generates keys from AES decryption (128-bit key). It takes seed as input: ...
user avatar
  • 339
2 votes
2 answers
989 views

Can I use the output from a DRBG directly as K for AES, or do I need to use a key generator algorithm?

NIST has 3 validated "Recommendation for Random Number Generation Using Deterministic Random Bit Generators" (DRBG's) that are based on NIST SP 800-90A: Hash_DRBG (based on hash functions) ...
user avatar
  • 123
3 votes
1 answer
4k views

RSA key pair generation and FIPS 140-2, 186-4

I need to securely generate RSA key pair and I need to have access to private exponent in order to process it further. What's the difference in FIPS 140-2 and FIPS 186-4 in connection with RSA key ...
user avatar
1 vote
3 answers
4k views

Generation of a cyclic group of prime order

I am trying to implement a cyclic group generator in Java, but I am running into some issues. In many cryptosystems, the following phrase is expressed during the key generation stage. Let G be ...
user avatar
3 votes
3 answers
16k views

RSA Key generation: How is multiplicative inverse computed?

As per Wikipedia, RSA keygen goes like this: Choose two distinct prime numbers p and q. Compute $n = pq$. Compute $\varphi(n) = (p − 1)(q − 1)$. Choose an integer e such that $1 < e < \varphi(n)...
user avatar
  • 143
3 votes
1 answer
3k views

RSA public key exponent generation confusion

Quote from Wiki: $e$ having a short bit-length and small Hamming weight results in more efficient encryption — most commonly $2^{16} + 1 = 65537$. However, much smaller values of $e$ (such as $3$) ...
user avatar
  • 246
5 votes
5 answers
11k views

Why is the private key generated first in public key crypto?

I'm still new to public key crypto. I'm trying to understand how it is that the private key is generated first in public key crypto? I would have expected the private and public key to be generated at ...
user avatar
2 votes
1 answer
608 views

How exactly is the output of the XOR step in PBKDF2 used?

I'm attempting to diagram PBKDF2 for a school project and I'm not 100% sure how to represent the XOR step. Specifically, I'm confused as to whether the output of the XOR step is used in subsequent ...
user avatar
-1 votes
1 answer
166 views

Issue about randomness : what if random looks "human" ? [closed]

I read a lot of stuffs about entropy/randomness. But what if a random generator (either digits or strings) once output a "human" patern ? I know it is very unlikely to happen, but if a random code ...
user avatar
-1 votes
1 answer
2k views

Problem with Python Implementation of Key Exchange part OTR Protocol [closed]

Being new to software development and crypto in general, I thought I would write a simple p2p encrypted chat app using the otr protocol detailed here: https://otr.cypherpunks.ca/Protocol-v3-4.0.0.html ...
user avatar
1 vote
1 answer
319 views

Generating the keys for the RSA cryptosystem in probabilistic polynomial time

In general every public key cryptosystem ``has'' a probabilistic polynomial time algorithm $G$ such that $G(1^k)=(\textrm{public key}, \textrm{private key=trapdoor})$; $G$ is called the key generator. ...
user avatar
  • 263
9 votes
2 answers
2k views

State of the art RSA key generation

I would like to know if there is an algorithm to generate a RSA key at the state of the art of the present cryptanalysis. Beside the key lenght I know there are some weakness in the choice of prime ...
user avatar
  • 3,225

1 2
3