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 AES Mode

Let's say I have an API that accepts Plaintext and IV as input parameter and returns the ciphertext. I know that API is using AES 128 encryption but now I need to identify which encryption mode (ECB, ...
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Can anyone detect which cryptography method is used from the cypher?

i want to know which cryptography method is used to encrypt below cypher. ...
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What is universal composability guaranteeing, specifically? Where does it apply, and where does it not?

I don't have a proper computer science education, so bear with my misunderstandings. UC is supposed to "guarantee strong security properties". From what I stand, if you have some secure ...
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27 views

Cracking Viginere Ciphers using same-length key used twice

Assuming I had two ciphertexts which were encrypted using the same key that has the same length with the ciphertexts. (However the keys didn't have any repetitions or features that would assist in ...
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Multi signature encryption (multiple people can decrypt)

I understand that multi sig transactions exist so that X of N need to sign to release a transaction. If only 1 of N is required I guess any of the recipients can spend. This made me wonder, is it ...
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ELGamal Exercice [closed]

I have an exercise about a modified Elgamal Encryption. The process of generate keys is the same: Prime number $p$ and element $a$ of order $q$ Random number $d$ where $d = K_{priv} \in [2, \ldots ,p ...
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Why encryption standard has fixed number of bits [closed]

In DES we use 56 bits, why can't we just increase the number of bits to have a more secure system? Why do we design a whole new AES for 128/256 bits? Some articles say it is for system compatibility, ...
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Designing a secure UDP-based communication protocol

SUMMARY UPDATE: I have changed the title of this question from "Using an encrypted packet counter as a counter value in AES-CTR" to "Designing a secure UDP-based communication protocol&...
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Plaintext with 'T' and 'E' alphabets missing and encrypted with Vigenere Cipher

I wrote the normal code to decrypt a Vigenere cipher encrypted text without knowing the key. But that won't work for this are two of the alphabets are missing and that would mess up the frequency ...
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Re-encrypt modified file section with AES-CTR

I am trying to encrypt a file using AES/CTR/NoPadding. The goal is to re-encrypt the new/changed blocks and leave the old ones unchanged then generate a new MAC. My thinking is that when the file ...
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Hard ADVGX Decryption [closed]

Decrypt the ADVGX code, without a keyword or matrix. FGGAADXXFAXFGGAGAGAAFDXXXAFGFGGGFXGXXAGGFXGDAGFX Important Hint:
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Does anyone know the encryption of this data? [closed]

I'm analyzing a game packet and I would like to know if anyone knows the encryption used here, because I don't know if it was the company itself that built this algorithm or it's some algorithm that I ...
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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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Multi Factor Encryption?

I got an alert last night to the keywords above and was curious, so took a look at the tor site flagged which is the following one: http://nsrz5iogimqwgeax3clpp6hvfy6viom2woy7dghgxes4sqk63r7svoqd....
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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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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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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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1answer
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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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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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1answer
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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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1answer
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What is the best way to encrypt whole partitions with Ed448-Goldilocks? [closed]

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.
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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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How does Microsoft's BitLocker Recovery Code work?

I don't trust Microsoft BitLocker because it is closed source, which makes it so people can't audit it. But now I'm really interested in how its recovery code works. In my own knowledge, encrypted ...
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1answer
54 views

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 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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Encryption and decryption of Request and response for REST API

I am working on encryption/decryption for the rest API. The client here can be mobile,desktop,web browsers,etc and all the requests will be made to a https endpoint. The main goal here is that the ...
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1answer
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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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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 this encryption algorithm built from MD5 secure?

I'm being asked to use an encryption algorithm in my code, and besides the fact that I'm sure there will be implementation faults that lead to vulnerabilities, I also have concerns about the algorithm ...
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1answer
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Bitwise operations in FHE

Im reading about FHE and the libraries implementing it (SEAL, HELib). I saw that SEAL doesn't support bitwise operations but I wondered if its theoretically feasible. For example, bitwise-ing XOR an ...
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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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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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1answer
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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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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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Are there actual consequences of padding oracle attacks?

I am writing a program that encrypts data in Python and heard about padding oracle attacks, but I think they are overrated (I mean, what are the real-world uses?) even for the old implementations that ...
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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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1answer
766 views

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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Can I encrypt a message by swapping bits in the text?

I have tried out an encryption method, in which I swap bits in the text. The text length is N bit, then I generate several random number pairs in the range 0..N-1, as [n,k] pairs. After that I swap ...
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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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1answer
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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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1answer
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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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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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1answer
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Security of AES under modification of Sboxes and/or MDS mixing layer

Is the security of AES algorithm increased by using many s boxes at the same time instead of using only one s box , and the same question for using many MDS instead of only one.
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1answer
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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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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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