All Questions

0
votes
0answers
7 views

how to compute Bit Independence criterion of SBOX?

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?
0
votes
1answer
21 views

curve25519 by openSSL

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 ...
1
vote
0answers
10 views

NIZK proof for Order-preserving encryption

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 ...
0
votes
0answers
10 views

Build a PEM file by having ec public key coordinates

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, ...), ...
2
votes
1answer
17 views

Static Diffie-Hellman in TLS

Static Diffie-Hellman (cipher suites with DH in their name but neither DHE or DH_anon - ...
0
votes
0answers
20 views

Zero knowledge proof with sum

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 ...
-1
votes
0answers
12 views

How is an Encrypted iTunes Backup's Manifest.db encrypted?

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 ...
0
votes
0answers
12 views

Security of HOTP over an unencrypted channel for controling an actuator

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 ...
1
vote
0answers
16 views

Do AEAD algorithms and encrypt-then-MAC mitigate external decryption oracles?

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 ...
0
votes
1answer
39 views

Explanation of trace function $\operatorname{Tr}_m(x) = x^{2^{m}} \oplus x$

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 $...
2
votes
1answer
77 views

Other than an exponent greater than 1, what are the considerations when creating a random 256-bit private key using Diffie Hellman?

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 ...
0
votes
1answer
67 views

Can you defeat AES-CTR's birthday boundary with a 2nd AES?

This follows on from How do I produce a stream of secure random numbers from AES-Counter mode? Consider then the generator:- $$ \operatorname{AES_{k1}}(n) \oplus \operatorname{AES_{k2}}(n) $$ ...
0
votes
0answers
21 views

I'm studying about differential cryptanalysis in DES. I need to make the DDT through python [duplicate]

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.
1
vote
0answers
32 views

Estimating the Security of SIS-Based Signature, by verifiying a subset of coordinates?

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 $\vec y = H(m) \in Z_q^n$ ...
0
votes
2answers
57 views

What is a cryptocoin made of?

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 ...
-1
votes
0answers
52 views

Will this software licensing scheme work?

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 ...
-2
votes
0answers
30 views

How do I solve B in terms of J and other params? xor cipher

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 ...
1
vote
1answer
33 views

Reversible Decryption in Symmetric Key Algorithms

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 ...
-5
votes
0answers
30 views

Audio Encryption

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 ...
0
votes
0answers
25 views

How many possible keys are in a columnar transposition cipher?

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 ...
1
vote
1answer
32 views

Does any problem arise when the order of an elliptic curve is equal to its prime field modulus? [duplicate]

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 $...
0
votes
0answers
11 views

Why in Efs file system (windows OS) is not possible to encrypt directly a compressed file? [migrated]

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
2
votes
0answers
39 views

Group Rings on Cryptography

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 ...
3
votes
1answer
1k views

In which public key encryption algorithms are the private and public key not reversible?

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 ...
2
votes
1answer
43 views

MPC and Secret Sharing in not Fully-Connected Network

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 ...
0
votes
0answers
42 views

Encryption/Decryption on multiple users using RSA?

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 ...
1
vote
0answers
84 views
+50

Signal Protocol - One Time Pre Keys (OTPK)

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 ...
0
votes
0answers
39 views

Modifying Elliptic Curve Parameters

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 ...
2
votes
1answer
57 views

How can the Enigma's plugboard settings be found with partially known plaintext?

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 ...
2
votes
0answers
29 views

Is McEliece secure with non-binary Goppa codes?

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 $...
0
votes
0answers
27 views

Alternate to distributing master key to every user in circle of trust

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 ...
-1
votes
1answer
77 views

Retreive secret key and IV knowing the plaintext and ciphertext?

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?
0
votes
0answers
18 views

ElGamal: different message with equal length random key

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? ...
0
votes
1answer
54 views

Understanding hybrid cryptography's concepts: signing and CA

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 ...
3
votes
2answers
78 views

Is lattice-based cryptography relevant in symmetric cryptography?

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?
0
votes
0answers
24 views

What is the cryptography involved in the initial setup of a cryptocurrency?

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 ...
0
votes
1answer
24 views

Are hashes only used to confirm data integrity when used for distributed ledgers?

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 ...
1
vote
1answer
65 views

What is the most efficient lattice problem solving algorithm?

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 ...
0
votes
2answers
82 views

$\alpha^{2^{m} + 1}$ is a generator of $\operatorname{GF}(2^m)$?

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 ...
2
votes
0answers
143 views
+100

Can future Bitcoin hashes be considered a good source to generate random numbers?

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?
0
votes
0answers
48 views

Is my approach for authenticated key derivation based on a master key secure? [on hold]

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 ...
-1
votes
0answers
17 views

Iinformation Security basic literatue [on hold]

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 ...
0
votes
0answers
44 views

Controlled randomness? [on hold]

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 ...
-1
votes
0answers
47 views

Cipher Classification

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 ...
2
votes
0answers
22 views

Proving a commitment hides the value hidden in an encrypted puzzle

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, ...
0
votes
0answers
31 views

What is the “most secure” way to public/private encrypt a 64 bit value? [on hold]

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 ...
2
votes
0answers
30 views

Are Fujisaki commitments binding if the factorization of the group is known?

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 ...
0
votes
1answer
48 views

How does sha-2 with fewer rounds work?

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 ...
0
votes
1answer
36 views

Are there any classical proven secure cryptographic algorithms other than OTP? [duplicate]

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 ...
0
votes
0answers
27 views

The ECC private key is generated with 0x00 at the beginning.(prefix)

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 ...

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