All Questions

Alice, Bob, and Charlie are working on three projects. Alice is the manager. At the beginning of each day, she chooses one project to work on (this choice is based on her preferences and is not ...

(This is inspired by this question 1; have also read this question 2 but it's one-time pad) I would like to know, given two message $m_1$ and $m_2$, as well as public keys $(e,n_1)$ and $(e,n_2)$, ...

What's the difference between a one-way hash function and a cryptographic accumulator? Somebody can explain it in simple way?

One time pads have the disadvantage of running out and renewal can lead to discovery. What are the vulnerabilities of this proposed mechanism: A single one time pad of random numbers is used. The ...

I’m trying to figure out how I could create a private group that was P2P yet still allowed someone to moderate members (no public access to messages). I’m assuming standard hybrid encryption (RSA/EC + ...

This question doesn't cover any technical aspects of PQC but I would want to know if undergraduate computer scientists study at a good level any of the available PQC schemes in literature during their ...

I am working with an embedded system that accepts firmware updates only if they are validly signed by a particular 2048-bit RSA private key (the embedded system's bootloader knows the corresponding ...

So I am at the same step as someone from math.stackexchange but he never recieved an answer so I will copy-paste his question here: Say, for N = 90283, I compute bound 𝐵=𝑒(12+𝑜(1))(ln(𝑛)ln(ln𝑛√))...

My textbook states, that the DDH-assumption is not satisfied when we use the group $\mathbb{Z}/p \mathbb{Z}$ and demonstrates an attack using Eulers Criterion. After that, it states that one should ...

I am trying to generate Ed25519 keys based on a 32-byte seed. According to RFC 8032, in order to create the public key, you have to take the private key, hash it with SHA-512, prune it, and then use ...

So I downloaded the Breach Compilation (the 1.4 billion usernames w/ respective passwords). When doing so, the friendly dev-like homies they are over @ github where the .torrent file for the latter is ...

I just read about Diffie–Hellman key exchange and was wondering how the value created from that can be used for any encryption method. Here is a link of where I read it from.

In an correct implementation of X25519+XSalsa20+Poly1305, I think I have the right understanding in saying that the Poly1305 message authentication code is a ...

For the sole purpose of learning, I am trying to figure out how disk encryption software is able to recover password of an encrypted disk using a challenge response mechanism. Th recovery process ...

How to compute the complexity of ElGamal ECC and Menezes-Vanstone ECC?

Twofish was one of the finalists in the last cipher competition together with Serpent and AES, where AES won. Do you know of any cryptanalysis on Twofish and if its considered "broken" or still ...

I am currently investigating threshold (EC)DSA signature scheme. In many schemes, there are two phases -- setup phase where necessary computation for random value generation and secret sharing setup ...

An adversary wants to find $a$ in $$m \equiv g^a \bmod P$$ He knows prime $P = 2 \cdot c \cdot k +1$ with it's primes $c,k$, value $m$ and $g$. And he also knows that $g$ only has an order of $k$, ...

Say that there are different live situations where you have to select own PIN numbers. Can someone say if it is possible to guess a 8 digit pin within 3 tries, given any methods or resources? Is ...

What are the latest advances in fully homomorphic encryption? First of all, I am interested in cryptosystems based on LWE / RLWE and NTRU problems.

For example, I'm using AES-CTR. I use fixed (random generated) key and random IV. I know that I have to encrypt key but I don't know about IV. If I will encrypt 1 block of data with fixed key and ...

For the AES-GCM mode within many cryptomodules, their FIPS-validation certificates list the options: Payload Length: 504, 512, 1016, 1024 AAD Length: 0, 504, 512, 1016, 1024 For example in OpenSSL, "...

I'm reading the paper "Differential Cryptanalysis of the Data Encryption Standard(2009)" and I was stuck in a certain part while reading it. In chapter 4, they explained about differential ...

I saw in another thread: Is using 7-8 random words from all words of a language as password a good idea? These calculations: If we assume that English has 171,476 words. Then with 8 words the ...

Can anyone tell me how to measure the security force of ElGamal ECC. and Menezes-vanstone ECC.?

Is there a way to prove/verify that an exponential ElGamal ciphertext of a message representative $\widetilde{m}=mG$ is well-formed, meaning that $r_1 = r_2$ in: $$C = (R, S) = (r_1G, \widetilde m + ...

I am looking for a curve with a bilinear pairing of safe prime order. I.e. a bilinear map $G \times G \rightarrow G_T$ where $|G| = p$, $p = 2q +1$, and $p,q$ are both prime. Is it feasible to find ...

Given a short Weierstrass elliptic curve $C$ over $F_p$ and a point $(x, y)$, it is easy to verify that $(x, y)$ either satisfies the curve equation (on-curve) or does not (off-curve). In the case ...

I'm building a website. I have an API which takes 2 parameters: delete_user(user_id, hash). And there is method to evaluate hash using SHA512: ...

First if this is the wrong place to post this please forgive me. I know my passphrase. I don't remember specifically how I entered it. ex. If the phrase is "The house at the end is blue and white. I ...

I like crypto, but I'm a bioanalytical chemistry person by trade. I like this algorithm and was wondering if I could use it to encrypt partitions like a MBR that prompts a passphrase, like BitLocker.

I am working on a puzzle and think there is a message hidden in one of the files that is a BMP file. I am wondering if there is a program somewhere that could find it?

Here is what I mean with "Mickey Mouse Version": CHARLIE makes a keypair key1 and key2 ...

I want to create implementation of AES-CBC. I have created this code: encryption process: ...

Although the ElGamal scheme states that the message $M$ must be $1 \le M \le p-1$ in this paper: A Secure and Optimally Efficient Multi-Authority Election Scheme they propose a method where the ...

Per NIST SP 800-90B – Section 3 – Entropy Source Validation : This Recommendation provides requirements for validating an entropy source at a stated entropy rate. Validation consists of testing by an ...

I'm looking for a non-interactive proof of work scheme. I want for it to (1) be faster to find solutions to if you're in the possession of an arbitrary secret, like a private key, and (2) for the ...

I read this question in my book (that doesn't have a response). 2DES is doubly more secure than DES? I know that 2DES can be attacked from meet in the middle ...

I am new to cryptography and have a question. If I try to wrap some key using an AES key using DES3_CBC_PAD as a wrapping mechanism will this go to work? I am doing this operation inside an HSM.

there is a Scrypt cipher which is used for exmaple by some cryptos like LItecoin for their mining algorithm. I never heared of scrypt. I know eg SHA256 which is well analyzed and considered as secure ...

There is a scrypt cipher that is used for example by some cryptos like LItecoin for their mining algorithm. I never heard of scrypt. I know eg SHA-256 which is well analyzed and considered as secure ...

I want to do "hash visualization", i.e. derive a human-meaningful information from a hash, like a phrase or an avatar. But the current techniques usually don't use many bits, for example tripphrases ...

Is it possible to ever have a commitment scheme that is statistically binding but not perfectly binding? The sender would be computationally unbounded, hence could always computationally trudge ...

Here's a question. I have a file that have to be encrypted with strong cipher (I've choosen AES-CTR-128). I'm using MVC 2019 to compile C++ program. Firstly, I create RSA-2048 key pair (public and ...

I've a couple of questions about my knowledge of the modern and secure use cases of vigenere. I'd like to know whether or not they'd be considered secure by todays standards - By that I mean easily ...

I am using sts-2.1.2 (NIST test suite for random numbers) in Ubuntu 16.04 for testing random numbers and I've installed it successfully. However I don't know how to perform test on random numbers, how ...

This is a semantics Question. Typically, in many asymmetric schemes, for this question specifically, digital signatures, we see that designers describe the key given to the verifier as Public Key. ...

PKCS11 cryptoki version 2.40 Current mechanism specification (section 2.8.5), says below statement for AES CBC wrap: For wrapping, the mechanism encrypts the value of the CKA_VALUE attribute of the ...

TL;DR: Is there such a thing as a hashmap whose contents cannot be read unless you have the right encryption key, and where each encryption key only works for a specific key value pair? More context: ...

Given that much of our ECC crypto primitives provide “only” 128-bit security when defined over a 256-bit curve due to pollard-rho, is it then still safe in 2020 to consider 128-bit security safe for ...