All Questions

Filter by
Sorted by
Tagged with
1 vote
1 answer
16 views

What is the standard security and leaky security, and the relation between the standard/leaky security and the leakage function?

Recently, I read some security proofs about the secure multi-party computation (MPC) protocol, which includes statements about information leakage, such as the security proof below from the paper CWL+...
Yang's user avatar
  • 150
0 votes
0 answers
33 views

Generating UUID from Keccak-256 hash

Is generating Keccak-256 hashes with timestamp + nonce (ensured to be unique for each run), and taking its most significant 16 bytes sufficient to generate random V4 UUIDs? Obviously the 13th hex ...
Ahmet Yazıcı's user avatar
0 votes
0 answers
23 views

Mysterious number series logic [closed]

(8,5,6) (16,9,10,12,7) (32,17,18,20,11,24,13,14) (64,33,34,36,19,40,21,22,48,25,26,28,15) Above four series are according to power of 2. The first row is 2^3 second row is 2^4 third row is 2^5 and so ...
UnpluggedTrio's user avatar
-1 votes
0 answers
16 views

How is sharegen computed without trusted third party in GHKL08 [closed]

https://eprint.iacr.org/2008/303 The protocol here relies on a subprotocol sharegen but i cannot understand how it is computed. Please explain.
Dhakshith's user avatar
0 votes
0 answers
39 views

Differential cryptanalysis of modes of operation

It is not quite difficult to understand the idea of differential cryptanalysis applied to a standalone block cipher. The method investigates, how differences of plaintext evolve while going through ...
Georgy Firsov's user avatar
0 votes
1 answer
86 views

Is a prime shifting method for RSA modulus generation safe?

I have a prime number, $p$, with $n$ bits. To generate a new prime number, $q$, I shift the bits of $p$ from left to right by a certain length. For example, if $p$ is represented as ...
Lisbeth's user avatar
  • 497
-1 votes
0 answers
24 views

Is this forum ok to post a factoring problem and ask for help fixing it? [closed]

One of my factoring methods works correctly sometimes, but other times it misses the factors, or is off by a square number from the the target product (the product of output factors is off by a square ...
Zekchelovek's user avatar
2 votes
1 answer
38 views

Rationale for BLAKE2 message schedule?

BLAKE2 uses a message schedule I did not see before. It uses permutations of pieces of the message block. The BLAKE2 book did not state the rationale for such a choice and how it contrasts with the ...
LightTunnelEnd's user avatar
1 vote
0 answers
55 views

Identified Performance Discrepancy in my AES addRoundKey: Slower than Expected

Problem I'm working on an AES implementation in C++, and I have been testing the performance of my code, and its functions. I've noticed a significant performance slowdown in my 'addRoundKey' function....
Lachlan's user avatar
  • 101
2 votes
1 answer
63 views

1-out-of-2 Oblivious Transfer with RSA

I'm trying to implement a simple 1-out-of-2 Oblivious Transfer with RSA. I was checking the code and tried to work it step by step. The 2 messages by Alice, let's say, are $m_0 = 7$ and $m_1 = 9$. Bob'...
Guest's user avatar
  • 21
1 vote
1 answer
51 views

Difference between a a doubled point and a point from point addition

Are all doubled points on an elliptic curve even, meaning if you compress the point, it will have '02' plus the $x$ coordinate? If not, what distinguishes a doubled point from a point resulting from ...
Dev Tenji's user avatar
0 votes
1 answer
21 views

How IKE authentication happens? what's the role of HASH_I & HASH_R, and how it gets verified by each parties? and where SKEYID_a gets engaged?

Dears, In RFC 2409 "The Internet Key Exchange (IKE)", its mentioned there are four available authentication methods for IKE, there are different calculations for SKEYID for each method and ...
Asem's user avatar
  • 1
3 votes
2 answers
629 views

How much entropy is lost due to collision?

If entropy is hashed with SHA-256 for example, and the input has exactly 256 entropy bits, how much entropy is reduced after hashing due to collision? Is there any reference that explains how to ...
Daniel Ghattas's user avatar
2 votes
0 answers
38 views

What's the lattice dimension of the uSVP for attacking CRYSTALS-Dilithium-128?

I am trying to understand the process of transitioning from a NIST standard to the attacks based on of the Unique Shortest Vector Problem (Unique-SVP). Specifically, I am working with Crystals ...
asdf's user avatar
  • 324
-1 votes
0 answers
34 views

Encrypted text question [closed]

I’m new here and I dont even know if I’m at the right place. I have a question about encrypted text. The thing I want to know is… let’s say someone sends me encrypted text Example: ...
Nik's user avatar
  • 1
2 votes
1 answer
258 views

Choosing (key,plain) to produce zero state in middle rounds of AES encrypt

I was told in passing that (key, plain) pairs could be chosen to produce a zero state in AES encrypt in some middle round (say 5). [The application here being to side-channel leakage assessment.] ...
yoyo's user avatar
  • 391
0 votes
1 answer
76 views

Hash Collision: Weak and Strong Resistance [closed]

On average, against a 128-bit-long key, how many more hash computations would an attacker need to perform to break weak collision resistance compared to breaking strong collision resistance? In other ...
Tườngg Trần's user avatar
1 vote
0 answers
29 views

Privacy-Preserving User Tracking Across Systems with Homomorphic Encryption or hashing

I'm working on a project where we have three different software systems—let's call them A, B, and C. Systems A and B handle user data identified by phone numbers and want to send user actions to ...
Mr Alihoseiny's user avatar
-1 votes
0 answers
36 views

Determining the vulnerability of BTC in the presence of output RSZ with the entropy of mutual relations [closed]

I found the program as I understood from the description of the search for mutual entropy of different groups of RSZ output signatures from one wallet to bitcoin. Who has heard anything about this ...
Man1133's user avatar
1 vote
0 answers
18 views

Search the LWE problem

When designing the search LWE problem, how do you set the dimensions of the A matrix? Or under what circumstances can I use very few matrix dimensions to achieve 128-bit security? Up to noise level? ...
Caimei Wang's user avatar
0 votes
0 answers
28 views

Requesting some recommendations for research topics on Signal protocol [migrated]

I am a beginner in Signal protocol. In my opinion, Signal protocol is already a very mature protocol, so I would like to ask What are the other worthwhile problems about Signal protocol that can be ...
HelloSpace's user avatar
0 votes
0 answers
81 views

Rate the security of the following MAC

Ok we know when we add a random IV in our encrypted MAC became useless and the IV can be forgery, then our encryption scheme becomes vulnerable to chosen plaintext attacks. According those proves : ...
Poseid0n's user avatar
2 votes
1 answer
48 views

Learning the LWE secret with advice

I am trying to argue about the hardness of LWE, but in a setting that is different from the standard one. Consider the task of learning the LWE secret $s$ from noisy samples. The specifications of the ...
BlackHat18's user avatar
2 votes
0 answers
23 views

How to distribute share that sums to 0 without a dealer?

I am looking for a protocol where each party generates a share such that $\sum_{i\in [n]} s_i =0$ where the shares should remain secret. The adversary may corrupt n-2 parties, and the parties can be ...
Doron's user avatar
  • 99
3 votes
2 answers
486 views

RSA perfect square phi

So I've been learning about RSA for quite a while (mainly by playing around in CTF competitions) and I came across an interesting problem. The other day I was looking to create a challenge in which I ...
Anonymous's user avatar
0 votes
2 answers
64 views

Cannot get RSA encrypt and decrypt to work in hardware and online calculator

I am attempting to get a hardware implementation of RSA working but I am having trouble with encryption and decryption. First, I ran these commands to generate the keys: openssl genrsa -out private-...
Jordan Krim's user avatar
0 votes
0 answers
33 views

Encrypting a number with a key of smaller size [closed]

How do I encrypt a 12 bit number using a 4 digit code?
Adoma's user avatar
  • 1
1 vote
0 answers
24 views

Bounding the commitment min-entropy of NTRU version of BLISS

I've read [DDLL13] paper and want to understand how the lemma 3.4 is changed for NTRU version of BLISS. In the naive construction of BLISS, the commitment entropy is bounded in Lemma 3.4 as below: $$ \...
dkzlfk12's user avatar
2 votes
0 answers
55 views

Tor Key Exchange Client - Middle Node

I am currently exploring the workings of the Tor network, specifically how the Diffie-Hellman (DH) key exchange protocol is employed to establish shared secret keys between the client and each relay ...
Elian's user avatar
  • 21
0 votes
1 answer
63 views

Z-coordinate in Jacobian coordinates

secp256k1 Generator:(G_X, G_Y, 0x1), secp256k1 any public key using affine coordinates : B=(X, Y) secp256k1 any Public key using jacobian coordinates:BB=(P_X, P_Y, P_Z) (B's private key)==(BB's ...
bnsage123's user avatar
1 vote
1 answer
130 views

Do we know that LWE is harder than Ring LWE?

The plain, normal-form, decisional LWE problem over $\mathbb{Z}/q\mathbb{Z}$ is: given a uniformly random $n\times n$ matrix $A$ and vector $b\in \mathbb{Z}/q\mathbb{Z}^n$, decide if $b=As+e$ for ...
Sam Jaques's user avatar
  • 1,105
0 votes
0 answers
24 views

Can't figure out the encryption [closed]

The ciphertext: Fubswrulqwb lv wkh sudfwlf dqg vwxlv ri whvwlf ryhu wklv xvhvwlq ri dwhvhvhfuhv ejwhfq. Pruh jovqshq, fubswrulqwb lv deyqxbuwlqj dqg exsduqbg rqrq ykiwhk vdssrkwxmtqj dqg wkhslnkrdq ...
anonencryption's user avatar
6 votes
2 answers
637 views

Kyber 512 Security Level Issue

So I read parts of the following article: https://blog.cr.yp.to/20231003-countcorrectly.html But I quite dont understand it. NIST assumes Kyber 512 is just as hard as AES128 nowadays, in presence of ...
user112982's user avatar
0 votes
0 answers
63 views

Random Bit Generation [closed]

I am new to cryptography , and I am trying to recreate the RSA 1024 bit encryption algorithm from scratch.I was wondering how I could make a CSPRNG from scratch to generate 512 bit primes for RSA. ...
stealth's user avatar
1 vote
2 answers
740 views

In RFC 2313 (PKCS1/RSA) said you could recreate the Private key from 'n' and 'd', which later versions removed. Why?

RFC 2313 has this specific callout: ...
rip...'s user avatar
  • 113
3 votes
0 answers
79 views

Impossibility of uniform generation in random world

I was reading Limits on the provable consequences of one way permutations by Impagliazzo and Rudich when I got stuck on a sentence. First of all, they define a polynomial relation that is any relation ...
Pur2all's user avatar
  • 48
0 votes
0 answers
50 views

How to prove that signature hash is wrong without reveal message

Let's say we have Bob, Alice and third party. Bob make message signature hash and upload to third party, then encrypt message with Alice pub key and send it to Alice Alice receive message and decrypt ...
byXrom's user avatar
  • 3
0 votes
0 answers
27 views

How to anonymously poll for information in a small group of people?

A company wants to poll employees about their view of the company (by using a web system, say). They would like to do it anonymously, but they don't want people filling out forms more than once. An ...
user1145880's user avatar
1 vote
1 answer
77 views

Probability when representing message as a point on elliptic curve

There is a very popular method to represent a message $m$ (number) as a point on elliptic curve over a finite field: Set $i = 0$ Check whether $m'=m\cdot K+i$ is on elliptic curve. If not, try again ...
Ape Tim's user avatar
  • 13
0 votes
1 answer
45 views

How do bad actors manipulate game results in real time within 'provably fair' gaming systems?

Ive been assigned research involving online gaming companies and their use of cryptographic algorithms to produce 'provably fair' results. The largest player in the industry uses a method involving a ...
Joey Jolly's user avatar
1 vote
1 answer
200 views

Recursive NTT for Kyber

since the NTT is a variant of the DFT respectively FFT, it seems possible to implement a recursive algorithm for the NTT of Kyber with a divide-and-conquer concept. This is the reason for my question ...
TreeBook1's user avatar
1 vote
1 answer
76 views

Point doubling for a point on Elliptic Curve (15,13) + (15,13) = (2,)

Consider the elliptic curve E1:y2=x3+7 over F17 with the base point G=(15,13) I am trying to compute point double of (15,13) i.e (15,13)+ (15,13) Expected point is (2,10) , however I am not able to ...
Sudhanwa Deo's user avatar
0 votes
1 answer
106 views

Possible to encrypt message without knowing recipient public key?

Assume Bob is sender and Alice is future recipient. In ideal situation Bob know Alice public key, and encrypt message with it. But what if Bob don't know Alice public key (he only will know Alice ...
byXrom's user avatar
  • 3
0 votes
1 answer
80 views

Prove that if $e.d \equiv 1 \text{ mod } pq$ then it's impossible to have $e.d \equiv 1 \text{ mod } (p-1)(q-1)$

I am studying RSA cryptosystem and here is the question that came to my mind. Let's pick $p, q$ to be two primes and $n = p * q$. From that we calculate Euler's totient function: $$ \phi(n) = (p - 1)(...
QuestionEverything's user avatar
0 votes
0 answers
41 views

Achieving sub-block non-malleability

I have a noisy one-way communication channel where data is sent as a series of words of width n bits. Assume n is a constant roughly in the range of 16...48. I don't want bit errors in one word to ...
Stephan Walter's user avatar
0 votes
0 answers
39 views

which DH protocol is safer in communication with given condition?

I am trying to understand some concepts such as DH problem and its variants. I have the following question from the book I read. (note that I translated the question from my language to english) ...
user avatar
4 votes
1 answer
175 views

Integrating Elligator mapping with libsodium Curve25519 implementation

I'm currently working on a project where I want to map Curve25519 public keys to uniformly random noise. The main idea is that when these transformed public keys are sent over a network, an outsider ...
Safari1811's user avatar
0 votes
0 answers
27 views

Short-input (<= 128 bit), short-output (<= 10 bit) MAC

I am faced with a problem of selecting an appropriate message authentication code (MAC) for a particular application. These are the constraints: I have two 64-bit integers $r_a$ and $r_s$ as input, ...
asnfkjsdx's user avatar
1 vote
0 answers
27 views

Dealing with MITM attack in e-voting systems

I've read many e-voting papers that use El-Gamal scheme which I recall is vulnerable to man-in-the-middle attack, yet I find no discussion or even mentioning of it in those papers. -Does anyone knows ...
ShAr's user avatar
  • 152
1 vote
2 answers
133 views

What scheme is the best for combining two shared secrets?

I'm developing a program that uses a hybrid Key Encapsulation Mechanism (KEM) scheme, employing Kyber and X25519, with each producing a 32-byte shared secret. What would be the best scheme to combine ...
Zola Gonano's user avatar

15 30 50 per page
1
2 3 4 5
598