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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Ensuring Data Security During Decryption and Re-encryption Process
Scenario:
Consider a scenario where Server 1 stores a 600-800 KB ebook encrypted with a certain private key. Server 2, a computation-purpose server, holds this private decryption key and get access to ...
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Prove with ZKP that I have encrypted a message $v + random\_number\cdot c$ given an RSA public key?
I want to create an application in which users can cast vote to blockchain in encrypted form using RSA. The private key will be revealed only after completion of the election.
My major use case is as ...
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Lightweight Asymmetric encryption algorithm
I'm an embedded systems researcher, and new in the crypto field. Actually, I need to know if there are any lightweight asymmetric encryption algorithm especially considering the time needed for key ...
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Speed comparison of encryption algorithms
I am trying to compare various encryption algorithms in terms of encryption duration, decryption duration, information entropy, NPCR, UACI, and correlation coefficients.
I used a Lena 256x256 ...
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Can I get individual data by paillier decryption if we send aggregated encrypted data?
Suppose there are different users data for $n$ Smart meters. We encrypt all the individual data and then add them together. After decrypting the summation, how can we retrieve the original data? We ...
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Is this self algorithm made private key for Diffie-Hellman key exchange secure
i created a function in javascript that creates my a for the DH exchange like this:
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Attack on the chosen plain-text RSA
Reading another user's question, a doubt came to me.
Suppose an RSA oracle exists, with which it is possible to interact to encrypt and decrypt some text. The oracle output is not the decrypted text ...
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Judgment of Results from NIST Randomness Testing
I am using the NIST suite to test the randomness of binary numbers and I have a 64KB dataset. I am confused with the results in finalAnalysisReport.txt.
I have the ...
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Finding bit positions of '1' in DES Encryption
In DES encryption, the IP table is shown. If the input
given in hexadecimal is "0020 0940 0000 F008", which
are the bit positions of "1" after the IP stage ?
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Encryption Algorithm that has no right key
is there an encryption algorithm where no key is wrong, but only one key is right?
essentially, if I encrypt some data with key X, any random "key" can "decrypt" the text, but ...
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Security of using key size larger than the message digest size in HMAC, with one time pads
I would like to know the security of using key size that is larger than the message digest (output) of a HMAC in one time pad encryption.
One time pads for the message and the key of HMAC are ...
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Is considered safe saving encrypting files using asymmetric encryption algorithm inside public environments?
I know restricting access of a file, is a important measure of security.
If we read the Payment Card Industry's Data Security Standard (aka PCI-DSS), we can see a requirement where control access must ...
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Inverse Permutation in Sequential Manner Per-XOR (𝑃𝑥−1)
I'm trying to understand a protocol proposed in a research paper. There is a step that involves computing inverse Per-XOR. The explanation along with solved example is given below:
"Perform ...
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where are ssh.com's crypticore and seed defined?
ssh.com's Tectia offers a few algorithms seemingly unique to itself. Chief among them: [email protected], [email protected] and [email protected]
Are these algorithms publicly defined ...
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Per-XOR computation
I have an assignment where I have to understand a protocol proposed in a research paper. The first step involves computing Per-XOR, but I can't seem to understand the explanation given. Below is the ...
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Best way to implement public blockchain for IoT?
I'm attempting to build a blockchain network of IoT devices that would allow public access such that any person around the world could push data to it and there would be an immutable record of all ...
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Security proof of this paper(Ciphertext-Policy Attribute-Based Encryption) which proposes the first CP-ABE scheme
I have trouble in understanding the security proof of this paper(Ciphertext-Policy Attribute-Based Encryption)
why are these two hybrids equivalent to the modified game above? It is obvious that $...
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openssl encryption salt length
when i was reading the latest source code of openssl, i found openssl enc has
an 8-byte (64-bit) salt length; because the same ...
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Digital Signature and Encryption Process / Hierarchy
I'm trying to get my head around this scenario. I understand that a private key can be used for signing a message to provide authentication and public key can be used for encrypting and its ...
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What if the hash code of the genesis block (first block in the block chain) is changed?
If so, what would happen? And if not, what are some limitations to it? The reason I am asking is because I just started getting into the cryptocurrency and am very interested in the cybersecurity ...
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ring signature with embedded data
As part of Spontaneous Anonymous Group (SAG) signatures of say 16 participants, the prover generates fake random responses for 15 elements and a real response at some secret index. I want to hijack ...
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Zero knowledge proof for the verifiable encryption
My question is about the verifiable encryption (Camenisch-Shoup).
in the Paillier cryptosystem, a message $m$ is encrypted using a public key (composed of $N$ and $g$) and a random number $r$, ...
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About Naccache-Stern higher residue cryptosystem definition
About the Naccache-Stern cryptosystem, I have found two different encryption algorithms:
In the original paper from Naccache and Stern, the encryption step is performed by calculating $c = g^m \...
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How to determine the shift key to decrypt a ciphertext which was encrypted using Caesar cipher?
So I found this question in a model paper,
Break ciphertext ”BJJY GPXF DI TJPM ZSYH” which is encrypted by a
Caesar Cipher.
This gives a meaningful plaintext if we use 21 as the shift key. So ...
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Using a hash instead of AES-CTR before XORing a plaintext [duplicate]
In AES-CTR, a key, a nonce and a counter are all encrypted to produce a value that is then XORed with a plaintext to produce the ciphertext.
Let's say we were to make a hash out of the key, the nonce ...
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Finding plain text given two cypher texts of the same plain text with two diffrent public keys
I want to find the plain text from two cyphertexts of RSA, encrypted with two diffrent public keys. I know that: for E((n,e),m) = c0 and E((n,f),m) = c1 , c0^x . c1^y mod n = m mod n = m (ex + fy=1) ...
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Is it a bad idea to use the same password and container size for multiple veracrypt container?
I'm new here and have a basic question about encryption. I plan to securely store sensitive data on a company computer. Being one of hundreds little branches of a bigger company, it is not possible to ...
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What does "192-bit equivalent" mean for WPA3?
In the Wikipedia page for WPA3 enterprise mode, it states that WPA3 has an "...equivalent 192-bit cryptographic strength in WPA3-Enterprise mode..." yet it also says that it uses AES-256-GCM ...
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Is it theoretically possible to create an unbreakable cipher?
I know this question might sound strange, but is it theoretically possible to create an unbreakable cipher if we don't consider bruteforce? Some of us believe that it is possible to create ciphers and ...
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If you encrypt an image (AES), is it still an image and can you view it?
Can you encrypt an image (with AES) such that you can open it as a png/jpeg?
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Privacy-Preserving User Tracking Across Systems with Homomorphic Encryption or hashing
I'm working on a project where we have three different software systems—let's call them A, B, and C.
Systems A and B handle user data identified by phone numbers and want to send user actions to ...
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When to use Argon2i vs Argon2d vs Argon2id?
I've read the manual, and multiple articles / StackExchange posts about this topic, but still can't decide which implementation of Argon2 is best for my use case.
I want to securely encrypt passwords ...
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Cannot get RSA encrypt and decrypt to work in hardware and online calculator
I am attempting to get a hardware implementation of RSA working but I am having trouble with encryption and decryption. First, I ran these commands to generate the keys:
openssl genrsa -out private-...
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Safety of using non-encrypted hashes to identify encrypted data in a key-value store
I saw posts tangentially related to this, but not this one specifically.
I'm building a content-addressable storage layer where I'd like to store the contents encrypted. The question is what is a safe ...
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How to prove that signature hash is wrong without reveal message
Let's say we have Bob, Alice and third party.
Bob make message signature hash and upload to third party, then encrypt message with Alice pub key and send it to Alice
Alice receive message and decrypt ...
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How to create an EC point from a plaintext message for encryption
It seems that ElGamal encryption is also possible for Elliptic Curve cryptography. However, that requires the user to convert the message to a point on the curve. What strategies are there to derive a ...
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Possible to encrypt message without knowing recipient public key?
Assume Bob is sender and Alice is future recipient.
In ideal situation Bob know Alice public key, and encrypt message with it.
But what if Bob don't know Alice public key (he only will know Alice ...
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which DH protocol is safer in communication with given condition?
I am trying to understand some concepts such as DH problem and its variants. I have the following question from the book I read. (note that I translated the question from my language to english)
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Source of encryption scheme used in blockchain based IoT
I've found the following encryption scheme
UserA: $$sk_A, pk_A = sk_A \cdot G$$
UserB: $$sk_B, pk_B = sk_B \cdot G$$
Enc: UserA
$$u \in \mathbb{Z}_q^* \\
Y = u \cdot pk_B \\
S = H(U) \oplus m \\
C = (...
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Cryptography to tackle deepfake, proving the photo is original
Deepfake technology has become very difficult to tackle due to sophisticated machine learning algorithms. Now, even when a journalist or bystander provides photo or video evidence, the culprit denies ...
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ElGamal signature scheme problem and unsure whether my calculations are wrong or that's the answer
Trying to solve problem with verifying a message through the ElGamal signature scheme and I end up getting two different values.
I'm given a prime number p=881
, e1=3,
d=60
, and a random value r=11
. ...
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Does combining a stream cipher and block cipher produce any vulnerabilities?
In particular, AES-CBC with Blake2b for HMAC combined with xChacha20-Poly1305.
The scheme is to encrypt with xChacha20-poly1305 first, using a key derived from a high entropy password using argon2id ...
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Assistance required with a suspected Nihilist Cipher text associated with a 1948 Cold Case [closed]
I have found a cipher text that shows up as a Nihilist Cipher when entered into the dCode cipher identifier. The text was found in a torn slip of paper bearing the words TAMAM SHUD, the last two words ...
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How to require possession of arbitrary data to decrypt a file?
I have pairs of files A and B both of arbitrary size and contents (for any pair of files, A could be significantly larger than B or vice versa). I want to be able to 'encrypt' A in such a way that I ...
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Decrypt RSA knowing N, invp, and invq
im having a problem while solving a RSA problem, so i have python script to create a RSA key and cipher, from that i have n, invp, and invq. so my question is possible to decrypt the message only with ...
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In RSA, how to calculate the private exponent 'd', after choosing 'e'?
Seems there are 2 ways:
d = (ϕ(n)*k + 1) / e
In this case, need to choose a proper integer k.
Question 1: How to choose k, just try positive integers start from 1, ...
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Is it secure to encrypt an authentication token using another possibly hashed authentication token?
I'm working on a web app ("main") which acts as a central access hub for several other web apps ("children"). The users are supposed to authenticate in the main app, resulting in a ...
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Hard to guess ciphertext
Is there an encryption scheme where it's hard to guess a valid ciphertext without knowing the key and the scheme is CPA secure?
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Is gcd(e,p−1)=1=gcd(e,q−1) similar to gcd(e,phi(n))=1?
I wonder, is $\gcd(e,p−1)=1=\gcd(e,q−1)$ similar to $\gcd(e,\phi(n))=1$ ??
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Difference between Key Scheduling and Key Generation?
I am a little bit confused in the terms i.e Key Scheduling and Key Generation. What is the actual difference between these two terms? According to Wikipedia, the terms are described as:
Key ...
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