All Questions
28
questions
1
vote
2
answers
316
views
Hamming Distance and Avalanche effect in Cryptography?
I am new to Cryptography and I know there are better ways to test a cipher's effectiveness out there but in this case I am trying to test a cryptographic algorithm's(AES,xchacha20,twofish) hamming ...
- 43
3
votes
1
answer
485
views
Is there any way to measure entropy of encryption algorithms in python?
I am new to cryptography and I am trying to find a way to measure ciphertext entropy of encryption algorithms such as AES, Chacha20, etc for a school project. Is there any way to do it on Python? I ...
- 43
0
votes
1
answer
217
views
If ChaCha20 only has 128 bits, is it secure?
ChaCha20 also provides 256-bit encryption, i.e, 2^256 possibilities of keys. But ChaCha20 is very fast, I think it provides at most 2^256 multiplied by decrypting time. 256-bit AES provides 254-bit ...
- 361
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
1
vote
1
answer
140
views
Is it possible to extend CMAC for ChaCha
CMAC is defined for AES for authentication. My question is pretty simple: is it possible to extend CMAC for ChaCha? Does it even make sense? I cannot find anything related and I am wondering if I am ...
1
vote
1
answer
431
views
Dividing an encrypted file is secure against classical or quantum
I'm very new to cryptography and this may sound so foolish. Often I read quantum computers will brute force keys. Let's assume this is true (does it depend on key length? or on an algorithm? I don't ...
- 13
4
votes
0
answers
153
views
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 ...
- 41
0
votes
1
answer
236
views
What is the lightest cipher that provides AES like security?
The lightest, or fastest cipher, that is well known and quite secure like AES. Is ChaCha20 a good option? Are there any better alternatives that are faster but still as secure?
- 25
2
votes
1
answer
5k
views
XChaCha20 vs AES 128 security and speed
Is XChaCha20 with 256 bit key and 192 bit nonce more secure than 128 bit key 128 bit key nonce AES, due to using larger key/nonce sizes? Isn't it supposed to be faster due to being a stream cipher? (...
- 25
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
2
answers
356
views
Faster cipher than AES256-CBC to use for DRM purpose
I have to develop a program using a "secret" locally stored encoded program for a school project.
For this I have to decipher the code on the fly to use it. The project recommend the use of ...
- 11
0
votes
1
answer
3k
views
How to choose between AES256-GCM, XSalsa20Poly1305 and XChaCha20Poly1305?
In libsodium, there're 3 symmetric encryption(stream cipher) which are AES256-GCM(Hardware-accelerated), XSalsa20Poly1305 and XChaCha20Poly1305(uncertain which version of libsodium add support to ...
- 159
2
votes
3
answers
465
views
Benchmark for CSPRNG as stream ciphers?
My limitation in my security protocol is that I want my RNG as CSPRNG and I also want it to be super fast.
If I use Salsa20 or ChaCha or AES counter mode, I don't get the desired speed. I want my PRNG ...
- 39
1
vote
1
answer
381
views
Can Stream Cipher be Used to Encrypt & Decrypt a File (Eg: .txt .docx .exe .zip)?
I was new to cryptography. And I know that in the world of cryptography there are two types of Symmetric Algorithms:
Stream Cipher (RC4, Salsa & Chacha)
Block Cipher (DES, AES)
And when doing ...
- 87
10
votes
2
answers
5k
views
Changing an Encryption scheme from AES to ChaCha20
I am using the AES cipher for my OTT platform. Almost all Chip vendors (ARM, Intel, etc) have built-in AES for faster and secure processing.
Now, how feasible it is to move from AES to ChaCha20? ...
- 650