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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xor DECODING without a key [closed]

How do I find the binary key that decodes FA41086EF9153F into a readable word in English. So Far, I have tried several keys of different lengths and nothing makes sense .. any one has any hints?
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Block cipher exercise CTR, CBC and ECB [closed]

I'm trying to figure out this exercise about CTR, CBC and ECB given Encryption Matrix [29->0, 11->1, 26->2, 1->3, 21->4, 4->5, 15->6, 31->7, 27->8, 28->9, 2->10, 14-&...
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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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Is there any way to save Email encrypted in Database and used as normal later?

I have a senario like " I want to save a email (like foo@bar.com) encrypted in Database (For example as 'asdjasjdna') ...
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Conditional decryption

Is it possible for one party to encrypt some data, and have another party (unknown to the first party) view that original data if a certain condition is met? I cannot find any information about this ...
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What schemes support atomic decryption+reencryption

What encryption schemes support this workflow? Vendor encrypts and publishes information for the client Client generates public and private key Vendor encrypts private information Vendor publishes ...
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What do people use non-extractable WebCrypto keys for?

I understand that non-extractable keys are secure because they cannot be exported. But I think many people would WANT to export their keys at some point if they don't want to risk losing everything. ...
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Machine Learning to improve Encryption algorithms

Can machine learning be used to improve encryption algorithms e.g.image encryption algorithms that use ECC ?
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Are there alternative ways to decrypt the public key to the public address

I've read and I discovered that it's not possible to derive the public key from the public address because of the hashing algorithm.... But is/are there any alternate way/ways that it can be ...
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What should the nonce value be for client-side encryption?

I am using the following chacha20poly1305 Rust library to encrypt some data in a desktop application. The user provides the key, which never leaves their device, to locally encrypt some data, and then ...
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What does TLS_ECDHE_ECDSA_with_AES_128_CCM means collectively. What is the signature algorithm and keys used here?

Will the signature algorithm be ECDSA and key (i) ECC key or (ii) ECDHE and ECDSA keys?
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post quantum cryptography

I am curious to calculate how well some encryption algorithms standup to quantum computers. Asymmetric cryptographic algorithms are vulnerable to compromise by known quantum algorithms, specifically ...
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How to tell which ciper was used on a file [closed]

I am trying to work out which ciper was used on a particular file, is the program that can do this?
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How to securely share AES key between two remote devices (client and server) through UDP protocol?

I have two separate system (client) and (server). I am having a problem which is to encrypt a message from the client and decrypt at the server. In order to do that, I am required to transmit my key ...
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Help determining the integrity of a proprietary (Falcom) sound format [closed]

I've been having a lot of fun with the game 'Zwei: The Ilvard Insurrection' by Nihon Falcom lately. The only problem is that most game files are in proprietary formats, namely .itm, .iti, .it3 files, ...
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Predict with a machine learning model without knowing the actual model values

Imagine Alice has trained a machine learning model. She wants other people like Bob to be able to use her model for prediction, but she doesn't want them to know the actual model. She wants the model ...
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Is any encryption system that changes keys for each session “forward secure”? [duplicate]

As far as i understand, a encryption system is forward secure if new session keys are generated for each session, which is also part of what wikipedia says about forward secrecy: By generating a ...
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What will be the MAC size of AES CBC-MAC if there are suppose 10 blocks in the AES CBC-MAC?

What will be the mac size of AES CBC-MAC if there are suppose 10 blocks in the AES CBC-MAC? Will it always be 128 bits MAC size for no matter how many numbers of blocks?
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Why random number used in RSA padding but not in AES?

I noticed that people use a random number in the RSA-OAEP padding scheme to avoid deterministic encryption. But in pkcs#7 people just use the padding size rather than some random bits. Doesn't it make ...
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Triple encryption with three separate keys, cascading vs. interweaving

When performing triple encryption using three separate keys, how have cascading vs. interweaving stacked up against each other in cryptoanalysis? Most of the references to triple encryption I see seem ...
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Calculate multiplication of a cipher matrix and a plain matrix

There is a matrix $A$ that we don't want to be revealed, and there is a matrix $B$ that is known. Is there any way to calculate $A \times B$ without revealing $A$? $A$ can be encrypted. But we don't ...
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How to generate the exact AES key in both client and server side?

I am using AES to create a secure tunnel for transmission of data. As the symmetric key encryption will require the same key to encrypt and decrypt, so we need to generate the exact same key for the ...
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Disrupting MITM attack against 3DES by intermingling plaintext and inter-mediate ciphertext between rounds

Let's say someone implements 3DES with three separate 56-bit keys and an attacker is attempting to execute a MITM attack. Here is the encryption plan designed to attempt to disrupt the MITM attack, or ...
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How to perform a known plaintext attack?

I have got the following documents: (1) The plaintext (2) The ciphertext (3) The python program used to encrypt/decrypt the text My goal is to find the key that was used to encrypt the plaintext into ...
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What encryption mode should I use to protect a packet but the integrity of the entire packet, including its header, is protected?

What encryption mode should I use to protect a packet, such that the payload of the packet is encrypted, but the integrity of the entire packet, including its header, is protected?
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Can I use ECC for encryption/decryption, just like RSA?

I'm familiar with RSA for asymmetric encryption. I also understand it's only supposed to encrypt small amounts of data (smaller than the key) so for encrypting arbitrary data I would typically ...
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Public key decryption?

In the article How Does the Blockchain Work? the writer makes the following statements: Since only you should be able to spend your bitcoins, each wallet is protected by a special cryptographic ...
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Why would you want to keep the Initialization Vectors Public?

So I was researching Initialization Vectors (IV) and even took a look at this thread... What is the main difference between a key, an IV and a nonce? ,but I was hoping that I could get some clarity. ...
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What is the size of a 1024-bit RSA cipher compared to its plaintext?

Let's assume we encrypt a 50000 bit plaintext with 1024-bit RSA and public exponent $e$ = 3: How big will its cipher be? When we increase the exponent to let's say $e$ = 216 + 1 = 65537, how big will ...
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How to perform encryption/decryption in a RESTful system? [migrated]

I'm not a crypto/security expert and have designed an architecture for encryption/decryption. I'm not sure if its full proof and want to know what people use as industry standard? I'm trying to ...
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What is the advantage of adversary if the random number repeats?

In proof of CPA-security of encryption scheme $(r, F_k(r)\oplus m )$ where: $F_k$ is a keyed function $r\in_R\{0,1\}^n$ is a random number, on page 85 of Introduction to modern cryptography we have ...
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DES : Is Double Encryption using same key twice equivalent to single DES using different key but of same size

If we encrypt a plain text using Double DES but with same key K1, Can we get the same result as if we would encrypt the plain text using single DES but with different key, say K2. What I'm asking is ...
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Implementing Standardized AES Algorithm

-- Hopefully this question fits here -- Time and time again, there is always one person who asked about creating their own encryption standard/cipher, and we all agree to stop them early on because we ...
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A known plaintext attack on Elgamal Cryptosystem where the random is fixed

Let the public key of Alice be $(p, g, h)$, where $p$ is a big prime $g$ is a generator for $\bmod p$ $h=g^a$. The secret key for Alice is $a$. Bob wants to communicate with Alice, so he encrypts ...
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regarding usage of hashing

I have a question regarding pitfalls of using only encryption. Suppose Bob and Alice want to flip a coin over a network. Alice proposes the following protocol. Alice randomly selects a value X ∈ {0,1}...
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Matrix cipher - symmetric or asymmetric cryptosystem?

Matrix cipher is defined by: a) Encryption: $C = K \times Z$, where $C$ is a cryptogram vector, $Z$ is a message vector and $K$ is encryption matrix (encryption key) b) Decryption: $Z = K^{-1} \times ...
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Cryptography that lets you conceal a secret, but also alerts others of the exposure of the concealed secret?

Is there such a cryptography where I can prove that someone decrypted an encrypted string? Say I wanted to attach a Bitcoin private key in some type of digital container, but in order to open this ...
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Is it safe to use RSA multiple times

Assuming I have multiple symmetric keys on specific machine(more than 10000 probably), can I use the same rsa key to encrypt all of those keys? I'm a bit concerned from a situation where multiple ...
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Modifying the One-Time Pad so that one key can be used two times

I'm currently working on a modified one time pad and I'm trying to use the encryption scheme such that the key will be used twice. I have written a small pseudo code but I'm stuck. Here is my attempt: ...
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best padding scheme for RSA

So i came across three padding scheme for RSA: PKCS1, PSS and OAEP. My intention here is to encrypt a file using AES key. then, encrypt the AES key with the RSA key and save the encrypted AES key ...
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Best suitable column type for openssl $tag,$iv,$key,$encrypted?

Which column type is best for storing $tag, $iv, $key, $encryptedData generated by openssl_encryption, and in which format I should save these values? I am using &...
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Symmetric-keys algorithms with different keys for encryption and decryption

The Symmetric-key algorithm article from Wikipedia states: The keys may be identical or there may be a simple transformation to go between the two keys. I am not aware of any symmetric-key ...
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Integrated Signatures and Encryption Scheme

Suppose we have a scheme ISE that combines $n$ signature schemes and one encryption scheme, where the same keys are used. It is composed of the following algorithms: Setup, KeyGen, $Sign_1,...,Sign_n, ...
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How to securely design REST API for Password Manager app? [migrated]

I want to create Password Manager where users can create their accounts and store website passwords. For the frontend, it will be a mobile app, but I need REST API as the backend data where the data ...
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Short one-time pad security

I am somewhat new to Cryptography and I'm struggling with this proof I came across in my Intro to Cryptography course. I understand the proof of security for a one-time pad: Pr[M = m | C = c] = Pr[M = ...
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Asymmetric Encryption vs Shared secret via ECDH

I'm reading RFC8291. Here's a figure on how Web Push Notifications work in general: ...
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What is Associated Data in AEAD?

I am trying to understand what is AEAD exactly. I am application developer not a cryptographer. I have been searching online for a while watched a bunch of Youtube videos, read through a couple of ...
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Salt: best practice

I'm a complete novice at this and in need of advice. I'm building an app that I've implemented a password encrypted backup feature into. I'm wondering about the best practice for handling the salt. ...
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Using sha3 as a deterministic source of psuedo-random bytes for xor encryption

The following code generates a deterministic stream of pseudo-random bytes, using SHA3. ...
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Shamir's Secret sharing for Key encryption

I have studied Shamirs Secret Sharing(SSS) scheme. Now my doubt is to how to apply this in real time applications. I have an application which receives encrypted data from server and decrypts the data ...

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