Questions tagged [encryption]

Encryption is the process of transforming plaintext using a cipher into ciphertext to make it unreadable to anyone except those possessing the key. Decryption is the process of transforming that ciphertext back into plaintext, using the key.

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identify how to solve this cipher please! its fun and a mystery

I have roughly 25 three digit numbers between 0 and 200, that are a cipher. if i know what some letters are (for instance a=2, c= 9, and f-3) then how can i solve for this?
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Data corruption to protect the encryption?

On KeePass help center it's stated that: ... if the header of the database (first few bytes) is corrupted, you're out of luck, too: the repair functionality won't be able to restore any entries (...
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How do you find the cipher formula for a cipher like this?

I'm new to ciphers and cryptology in general, so apologies in advanced. ((When I say I'm new, I mean I only started looking up cryptography in response to being given this cipher this morning, so I ...
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What's the difference beteween SIDH and SIKE?

I'm a semi newbie in crypto (I've had that uni course of discrete math that includes basic cryptography principles) and wanted to go a bit further in isogeny graphs. I have downloaded the C ...
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Equivalance of encryption and decryption in DES under bruteforce

I am studying the vulnerability of DES algorithm. Let there be a DES system with 5 keys, 56bits each. Encryption works as follows: (It's in this order on purpose) $C=DEC_{k1}(ENC_{k2}(ENC_{k3}(DEC_{k4}...
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Encrypting data before Saas-solution

The compliance department is asking me for recommendations on encrypting data before Saas-solutions. Meaning that the Saas-solution should not be able to see the data when stored and processed. ...
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What is the importance of superencryption?

Please, can any extensively explain the importance of super encryption in relation to attacks experienced by single standard algorithms
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Which encryption technique should be adopted to keep the search functionalities?

I am in exactly the same situation as described in this post. I must be able to encrypt data from a client workstation then send it to an untrusted server (encrypted at rest), then decrypt it only on ...
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RSA / RS256 Encryption with the public key I have

safe to say I'm a complete beginner when it comes to cryptography... I believe the example output below is some sort of RSA (or RS256) encrypted string, and was just curious whether it'd be possible ...
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Why Can't I Use an Nacl Sign Keypair for Encrypt and Decrypt Operations?

I'm aware that the difference between the NaCL sign keys vs the box keys is that the secret key that comes from the NaCL box keypair is the ...
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How does biometric authentication add protection to encryption schemes?

I'm wondering since at least 2 offline password management services,Passkeep and Keepass both use biometric authentication in addition to the master password. You need to possess the physical device ...
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ZKP proof of copying a vote without interaction with the copied

So I had a question about ZKP protocol, I had to create one by myself and I am not sure if it is valid.I'll try to explain, if you need any precisions, don't hesitate to ask. In an election system, ...
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A CERTIFIED DIGITAL SIGNATURE paper pg 20 - 25

Reference paper: "A CERTIFIED DIGITAL SIGNATURE" With reference to the image above which is from Page 20 of the attached paper. What is this new protocol that the paper speaks of here? What ...
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Recovering original bit vectors that constituted XORed binary vectors

I am trying to unscramble received data packets. Each packet is divided into 3 parts ($A$, $B$ and $D$) with equal lengths. In every packet, each of these parts are scrambled/encrypted with an unknown ...
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Lightweight cipher using only 8-bit operations

What is the most efficient (in cycles per byte) cryptographically secure symmetric cipher to implement using only 8-bit operations? Algorithms like TEA are great for embedded devices, but it is ...
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Increase encryption key length in Shamir secret sharing

Can Shamir's secret sharing work on any size of key?
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Encrypt clients files and shares

I have to encrypt data (files) of client on server side and only the client can read theses files (admin can't see name and content of file). To resolve this, I have the idea to just use something ...
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Is there any good attack model of HMAC?

Are there any good attack models of HMAC? Like how it can be attacked? If there are any possible attacks of HMAC I would be happy to know about it.
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Text cipher option that can decrypt the same ciphertext to two DIFFERENT and DESIRED outputs given DIFFERENT keys (and/or alphabet)

I have a pen pal that I discuss with. In our latest discussion it was proposed to write a short message that is ciphered and have the other one find what it is, given some clues. I would like to ask ...
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Vigenere Cipher Collision

I have been reading the book "Serious Cryptography" by Aumasson to begin learning about Cryptography. There was a part where the author suggested how encryption using permutation should have ...
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Has Telegram security been significantly improved with MTProto 2.0?

Telegram messenger's original encryption scheme, MTProto 1.0, has been shunned by most cryptographers for a number of reasons, like being vulnerable to IND-CCA attack; being unorthodox in general, ...
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Analysis of the Vigenere cipher

Im just starting out learning some cryptoanalysis techniques. I came across an idea which analyzes the vigenere cipher. Essentially the video explains that there is a standard english probability ...
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Seeking name of encryption algorithm

I found an algorithm described in my old math notes that I wanted to dive into further, but the name I noted is apparently completely wrong ("Bolson Adding"), so now I am trying to find the ...
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478 views

What is the meaning of "transcipher" (if such term exists)

recently I heard the term "transcipher" during a discussion (seems something related to double encryption using two different keys), but I was not able to find any information about such a term in the ...
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How do I calculate number of multiplication, exponential, and pairing operations in a cryptographic algorithm (signcryption/unsigncryption)?

I have been working on signcryption scheme and its security proof. I want to compute the efficiency in terms of number of scalar multiplication operation, number of exponential operations, and number ...
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GnuPG - provide encryption key for AES rather than deriving it from passphrase

I'd like to encrypt a file with AES256 and provide my own 32-bytes for the encryption, rather than having GPG derive it from the passphrase. I could not find such option, but I'm thinking about a ...
2 votes
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Textbook RSA with $e=3$ and short random message

This is a simplified version of a question I made long ago, that never got an accepted answer. It's given $N$ of $n=2048$ bit, assumed hard to factor, which two prime factors each are $\equiv2\pmod3$, ...
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Does TLS convert individual messages to ciphertext? If the network is breached, is the data exposed?

As far as I understand it, TLS creates a tunnel or channel or secure connection between the parties right? Where everything is protected? But hypothetically if the network gets breached, would the raw ...
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Would a "Triple AES" (in the sense of how Triple Des works) serve for a dramatic increase in safety?

The system requires to be as paranoid as possible regarding security. One of the few contemplated changes to the current design is to use multiple encryption. First proposal was to use Serpent on top ...
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encrypting a document with 2 different keys

Is there a way to encrypt a file with 2 (or more) keys and then access it with only 1? scenario : Bob and Alice have a tight memory and can only remember ONE key. Bob and Alice encrypt a file with ...
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Hello, I want to generate and transfer TPK to a 3rd party.hence, I need to create 3 ZMK components and share with 3 custodians from 3rd party

Below are the steps I have figured out for the same. GC( generate component) or OC (generate cand print component) Component 1, 2, 3 In order to share clear components with 3rd party, guess have to ...
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2 answers
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Prove a plain text belongs to encrypted data

Given an encrypted (RSA) message and it's original plain text, is there a way to prove that the plain text belongs to the encrypted message ?
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Cryptography methods that allow for multiple keys to be used?

I'm currently working on a webapp in which I'd like all nearly all user data to be encrypted, but accessible by multiple users (ie a doc encrypted should be decrypt-able by parties A, B, C, all ...
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How to secure confidential data in memory

I am currently working on password manager. So far I used one encrypted database file to store all the passwords and then decrypted it at runtime with a derived user-entered master password. All log-...
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163 views

Does a self-build random 256-key based on substition and permutation have the same power as an AES-key?

As far as understand AES takes 16 bytes, shuffles them and replaces every of the 256 bits via XOR. Then the same procedure applies to the next 16 bytes, and then again - until the entire file is ...
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How can JWE support an integrity check given that it uses a public key to encrypt the message?

As far as I know JWE (JSON Web Encryption) supports both integrity and confidentiality. I agree about the confedintiality because only the recepient with a private key can decrypt a message. What ...
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Provably secure and Practical ciphers

Are there any ciphers that are provably secure (reducable to a hard problem (including like factorization, not necessarily to NP-Complete or harder) ) are practical (not necessarily for too much ...
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Why Block Ciphers

I​ fail to understand what block ciphers can do that stream ciphers cannot. Also aren't they construct able from one another. prg(stream cipher) -> prf -> prp(block cipher) Any practical example ...
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I need an encryption algorithm that doesn't require keys and computationally easy to encrypt, hard to decrypt

I need an encryption algorithm that doesn't require keys and computationally easy to encrypt, hard to decrypt. Decrypting can involve brute force. If the algorithm can be applied again and again (...
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Is there any Cryptographic loop function that returns first input?

I want to use cryptographic function that returns the initial input or something related to it like its hash, the function should work like Encrypting some data or its hash, then encrypt the output of ...
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crib drag calculator error

I am trying to use https://toolbox.lotusfa.com/crib_drag/ for crib dragging with ciphertext1: 205, 130, 103, 236, 99, 15, 171, 227, 131, 10, 152, 5, 42, 187, 52, 143, 139, 204, 202, 108, 0, 146, 247, ...
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LWE with a binary matrix A

In LWE, we know that given reasonable public parameter $A\in \mathbb{Z}_q^{n\times \lambda}$, secret $s\in \mathbb{Z}_q^{\lambda}$ and noise $e\in \mathcal{X}^{n}$, random $r\in \mathbb{Z}_q^{n}$, $(A,...
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What is Plaintext-awareness?

Could you explain with an example what does it mean to be Plaintext-awareness. I have read the wiki definition. It says that "A cryptosystem is plaintext-aware if it cannot genenerate a valid ...
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Decryption using multiple keys

0 I have a PHP application which calls third party api with username and password embedded in the XML API call from my side. I would like to encrypt and store the username and password embedded in the ...
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Vigenere applied to encrypted data

What happens if you encrypt data with a good cypher that produces a cyphertext that looks random (say, AES but avoiding ECB mode), and then apply a Vigenere cypher to the encrypted random-looking data?...
1 vote
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Security of the encryptions, using a PRG for the keyGen

I recently got doubtful to the usefulness of psuedorandom generators(PRG) in cryptography. Based on Kereckhoff's principle, we always assume that the used algorithms are made public. So, when we use a ...
1 vote
1 answer
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How does AES GCM encryption work

Previously, I used AES CBC 256 with 256 bit key and 128 bit IV. However it seems slow so I decide to switch to AES GCM 256 bit key, 96 bit IV which has some parts I don't understand such as: Auth tag:...
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Is partial digest recognition possible?

TL;DR Does hashing a private key, then XOR[ing] the digest (twice recursively, with offset) on the secret have any glaring issues? Is partial digest recognition possible? Description User provides a ...
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What is the Standard to protect classified, Secret and Top Secret information?

Para 3 of Security Requirements for Cryptographic Module (FIPS 140-2) specifies the requirements that will be satisfied by a crypto module protecting sensitive but unclassified information. What are ...
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Can raw hash be used as secret key

I am trying to use argon2 hash to derive secret key to be used for AES-GCM , in package argon2-cffi in python there is a function argon2.low_level.hash_secret_raw(secret: bytes, salt: bytes, time_cost:...

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