All Questions
14
questions
2
votes
2
answers
109
views
Can you use ChaCha20 as one-time pad?
My knowledge of cryptography nothing beyond basic so I am by no means an expert, but I do know a bit of undergraduate mathematics including number theory.
I know that stream ciphers like ChaCha20 is ...
- 21
2
votes
1
answer
74
views
Choice of nonce for reproducible encryption
In my application I have an SQLite database that stores labels for images, like this:
IMAGE ID
LABEL
1
foo
1
bar
2
bar
3
foo
The LABEL column is indexed as it is important that I can efficiently ...
- 173
2
votes
1
answer
267
views
Does triple ChaCha20 have 256-bit post-quantum security?
Experts suggested 3DES when AES wasn't developed yet, since meet-in-the-middle attack, they suggested triple DES. Grover's algorithm, a quantum algorithm, weakens symmetric encryptions, how about ...
- 361
1
vote
1
answer
330
views
Age: stream cipher with public key cryptography?
I have some rudimentary cryptography knowledge but am by no means an expert.
I generally understand stream ciphers, such as such as ChaCha20-Poly1305, to be symmetric. I am wondering how age (https://...
0
votes
1
answer
157
views
Do multiple keys mitigate Grover algorithm?
Grover, a quantum algorithm, weakens AES and ChaCha20. Is it possible to use multiple symmetric keys to encrypt a message multiple times to achieve 256-bit security for quantum computers?
- 361
0
votes
1
answer
159
views
Encrypting two messages with the same content with different keys/IVs still secure if attacker knows they are the same?
I want to store two ciphertexts inside the same file.
The data stored in each ciphertext is the same (except for padding), but the data was encrypted with different keys and IVs. Both ciphertexts were ...
- 25
1
vote
0
answers
290
views
Implement deterministic authenticated encryption using libsodium
Note: this is my first question on stack exchange, let me know if you miss some details to answer and I will edit the question accordingly
Context
I'm willing to create a git encryption tool (...
- 11
0
votes
1
answer
190
views
Symmetric key as proof of ownership of a session?
I have a question, or rather multiple questions that all relate to the same topic.
I am building an application with both a frontend (FE) and a backend (BE). All communication between FE and BE is ...
- 101
8
votes
3
answers
3k
views
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 ...
- 81
3
votes
1
answer
936
views
Which is the best algorithm for large scale file encryption other than AES?
I've been looking for a fast, powerful and robust algorithm for encrypting large files with authentication .
I would like to implement the algorithm on my own without using third party software. I've ...
- 1,030
-2
votes
2
answers
207
views
Is there any vulnerability in this scheme?
We want to design a symmetric encryption scheme. Note that the following things are true for our system:
The plaintext P will change every time for a given user.
A user will choose a password which ...
- 11
9
votes
2
answers
5k
views
Does ChaCha20/Salsa have the same bit strength as AES for identical key sizes?
Does ChaCha20/Salsa have the same bit strength as AES for identical key sizes? In other words, does ChaCha20 with a 128-bit key theoretically require 2^128 attempts to brute force, as with AES-128?
...
- 1,434
4
votes
0
answers
147
views
Creating an SPN cipher from ChaCha20 or Salsa20's double round function
Given that ChaCha20's building blocks have been also used to construct a hash function, can the double round function from either ChaCha20 or Salsa20 be used to construct a secure SP-network cipher?
...
- 3,675
4
votes
1
answer
142
views
Symmetric encryption algorithms with large IVs and authentication?
Most modern symmetric ciphers require a nonce/IV. If the nonce is reused, security is lost.
If the nonce is large enough, it can be generated securely by using a CSPRNG. This avoids needing to keep ...
- 4,793