All Questions

I want to compute BIC's of my Sboxes, I found out some theses for that but I could not understand how to do it. Can someone help me?

How can i generate ec curve25519 keys using openSSL? When I run openssl ecparam -name curve25519 -genkey -noout -out private.ec.key I have this message ...

Suppose a cipher c=Enc(K,m), where Enc() is the order-preserving encryption scheme. Can NIZK be used to generate a proof to prove that c is indeed encrypted by m? The Schnorr NIZK is based on discrete ...

I have the coordinates (x,y) of eliptic curve point that is my public key. How can i build the PEM ( or DER ) file for my public key? I don't care about language (java, python, javascript, ...), ...

Static Diffie-Hellman (cipher suites with DH in their name but neither DHE or DH_anon - ...

All zero-knowledge protocols I have read so far for discrete log works like this: 1) Prover generate a random number $r$, creates a commitment $t=g^r$ and sends $t$ to the verifier. 2) Verifier ...

When you do an Encrypted iTunes Backup, it encrypts the data but it also encrypts the Manifest.db file as well, which contains the information about the rest of the iTunes Backup. How is the ...

I have a simple on/off actuator that I want to control remotely. I want to use available hardware: a pair of microcontrollers connected to a pair of wireless transceiver modules. Can HOTP algorithm ...

I'm curious about a possible attack scenario that I'm not sure exists. If it is possible, I'd like to know if and how AEAD algorithms and encrypt-then-MAC implementations protect against it. The ...

The following statement is from a paper (Partitions in the S-Box of Streebog and Kuznyechik) about S-Boxes: For all $ x \in \operatorname{GF}(2^{n})$, it holds that $x^{2^{n}} \oplus x = 0$. If $...

Let's assume that I choose the bits for my 256-bit private key exponent by flipping a coin 256 times. Are there any other issues, besides the randomness of the 256-bit private key to consider? For ...

This follows on from How do I produce a stream of secure random numbers from AES-Counter mode? Consider then the generator:- $$ \operatorname{AES_{k1}}(n) \oplus \operatorname{AES_{k2}}(n) $$ ...

I just made DES algorithm(encryption, decryption) using python. And I want to attack 1,2 4,8 .. round DES. For that, I need to make the DDT code. Could you guys help me to make the DDT? Thank you.

As I understood, the GPV signature scheme works as follows: KeyGen($1^n$) : Generate a Lattice with public $A \in Z_q^{n.m}$ and a secret trapdoor $t$. Sign $m$: compute $\vec y = H(m) \in Z_q^n$ ...

I want to know whether a cryptocoin is made of some piece of code or it is kind of a bill that says a person has transferred conceptual coin to another person when a transaction is published. If it is ...

I am trying to implement a software licensing scheme to prevent software privacy (as much as possible). After many, many hours of researching, what I've concluded is that there is no license scheme ...

How do I solve B in terms of J and other params? J (Encrypted) = {( [(B+C) ⊕ D] – E ) ⊕ (F–G)} ⊕ H I am new to this, so please provide as many resources as you can to help me get a head start on ...

I am currently learning the Internal Working of Symmetric Key Algorithms, like DES, AES, BlowFish, IDEA just to name a few. These are all quite complex Encryption alogrithms, which requires a lot of ...

I really need help. My idea is to create a music playback application in which it is impossible to take the music out of the application and the music is only readable in the application. Can I ...

In a book I am reading it says that the message "Common sense is not so common." (which has 30 characters, space and punctuation included) has a range of possible keys of 2 to 15, half the message ...

Regarding cryptographic schemes in elliptic curve cryptography, is there a problem with having the order of an elliptic curve being equal to its prime field modulus? That is, an elliptic curve where $...

EFS File system doesn't permit to encrypt directly a compressed file. The opposite process is clear because is impossible practically but this one i can't understand

Let $R[G]$ or $RG$ be the group ring where $R=F_q$ and $G$ is any group. Let $Dim(V)=\vert G \vert$. It's clear that $V$ has $\vert R \vert^{\vert G \vert}$ distinct $\vert G \vert$-tuples. This ...

The RSA public key encryption system has the characteristic that the public key and the private key can be reversed. That is, information encrypted with the public key can be decrypted with the ...

I have an interest in applications of MPC and Secret Sharing. My point of view is from fields of distributed computing and Game Theory. I want to generalize some results to arbitrary network ...

Supposing I have Alice that is the RA, Bob (who is a user) and Kate (who is also a user). For now I use RSA. Alice sends a message to Bob. Alice also sends a message to Kate. Bob and Kate exchange ...

In Signal Protocol one time pre keys are a key only used once by Alice and taken from Bob, they provide forward secrecy (If the identity private key and signed private pre key which were used to ...

For context, I was watching this bit of the video: which goes over this source code. The piece is about elliptic curve cryptography and how it works. I want to use some of this knowledge to make my ...

I don't quite understand the procedure described on wikipedia, is there a generalized procedure you can follow to rule out a pairing on the plugboard? For example, let's say the cipher text is ...

A binary Goppa code with codewords of length $n$ bits that can fix $t$ errors with a polynomial over $GF(2^m)$ can encode $k = n - mt$ bits long data. That is one needs to add $mt$ check bits to fix $...

I am designing an end-to-end encrypted file storage system where only the user should be able to access their own data. The best I could come up with is a system designed around a master key that is ...

If I use AES-128 in CBC mode, and I know the plaintext, ciphertext, and length of the plaintext padding, which is 15, can I retrieve the key and IV, using brute force or some special techniques?

This situation applies to ElGamal digital signatures: consider messages m1 and m2 which we will encipher with a random key. The random key has the same Hamming weight. Is this situation secure? Why? ...

After learning about symmetric encryption, public-key encryption, one-way hash, digital signature and digital certificate, I was tasked to think of an imaginary hybrid cryptosystem. I was thinking ...

I've seen that lattice-based cryptography works well with public key cryptography as well as cryptographic hashing algorithms, but does it apply to symmetric key cryptography?

I keep hearing that when a cryptocurrency is created it goes through an initial setup phase wherein cryptographic parameters are created that are used by the cryptocurrency network throughout its ...

I have a couple questions related to hashing and data. Please let me know if the questions I have are too broad for this site, or if clarification is needed. I have read a lot about hashing as it ...

I've recently become very interested in post-quantum cryptography, specifically lattice-based cryptography. As of this posting there exists no quantum algorithm that can perform better at solving ...

This is from a paper (Partitions in the S-Box of Streebog and Kuznyechik) about S-Boxes: Let $\operatorname{GF}(2^{2m}) = \mathbb{F}_2[X]/p(X)$ be a finite field of even degree defined by a ...

There are a lot of miners trying to calculate the next valid SHA-256 hash using random strings, so can I consider that generated hashes have good randomness? How can I prove it?

My goal is to be able to have a single Master Key and store this on a central machine. A client communicates with this central machine to request and receive a certified key derived from this master ...

I'm starting to study Information Security to write my Undergraduate thesis. What are the most famous and basic literature which cover the following topics: Principles (Availability, Integrity and ...

I would like to have a ten-round draft in my Fantasy Football league in which the ten teams are given a position in the draft that doesn't repeat. My league is really based on nine rounds after a ...

Is there a method of classifying classical ciphers into distinct categories like the whole scientific name system? What I mean is, is there system that classifies ciphers that are similar together as ...

I am making a protocol that has one missing piece. It involves 2 non-trusted party $A$ and $B$ and a semihonest third party $C$. This protocol has a contingency step where if $A$ leaves prematurely, ...

I want to encrypt a 64-bit value using a private key. The data size is limited to 64-bit, so the encrypted data must also not exceed the 64-bit limit. The receiver of the encrypted value should be ...

If I understand correctly, a Fujisaki commitment is as follows: $g^m \cdot h^r $ mod $n$, where $m$ is a message, $r$ is a random number, there exists $a$ such that $h^a = g$, and $n$ is an RSA ...

The wikipedia page about sha-2 states: Currently, the best public attacks break preimage resistance for 52 out of 64 rounds of SHA-256 or 57 out of 80 rounds of SHA-512 How exactly is the sha-256 ...

Boiled down to the core as I understand it: A cryptographic algorithm has provable security if it's unbreakable, even if an adversary has unlimited computational power / time. If my understanding ...

I created a private key using the prime256v1 curve. My purpose is to get a 32 byte private key. However, the private key is preceded by 0x00, resulting in 33 bytes. Why is this happening? The only ...