Linked Questions
28 questions linked to/from Disadvantages of AES-CTR?
19
votes
4
answers
5k
views
Is SHA-256 secure as a CTR block cipher?
Generate a 256-bit random nonce. XOR it with a 256-bit reusable symmetric key. This is x.
We represent numbers in simple binary instead of a counting function. <...
- 575
4
votes
1
answer
30k
views
Is regular CTR mode vulnerable to any attacks?
Regular plain CTR mode, is it vulnerable to any attack?
I plan to write a program to encrypt a drive with ctr mode. Would this be wise? Would AES be better?
When I look at this diagram, it looks ...
- 43
17
votes
1
answer
26k
views
Bit Flipping Attack on CBC Mode
To perform a bit flipping attack, the previous block is modified by using XOR. This results in an altered plaintext. However, now the ciphertext of the previous block is altered, hence it will result ...
- 311
12
votes
3
answers
3k
views
Using a Non-Random IV with modes other than CBC
The weakness CWE-329 is an interesting problem with CBC mode. However, does this same weakness affect the other modes of operation that rely upon an IV such as: PCBC, CFB and OFB? My gut feeling is, ...
- 1,486
3
votes
3
answers
4k
views
Is CTR more secure than CBC?
In cryptography, a block cipher mode of operation is an algorithm that uses a block cipher to provide information security such as confidentiality or authenticity. A block cipher by itself is only ...
- 73
13
votes
1
answer
6k
views
What are the rules for using AES-GCM correctly?
When using AES-GCM I know that I am supposed to use a new initialization vector every time I call the AES-GCM algorithm with the same key. What are other rules must be followed to use AES-GCM ...
- 611
2
votes
2
answers
5k
views
What is the difference between pseudorandom permutation/pseudorandom function/block cipher?
What is the difference between;
pseudorandom permutation
pseudorandom function
block cipher?
Very confused with the 3 terms and I am not good at advanced math. Can someone explain in plain word?
- 21
1
vote
2
answers
1k
views
How insecure would a cipher based on iterative hashing be?
I was just wondering how the following construction could be insecure. I can tell that known-plain attacks are possible, but I'm not sure about anything else.
Let the user pick a password and hash it ...
- 19
2
votes
2
answers
511
views
Does keeping IV secret increase security of CTR mode?
Let's suppose I encrypt something with CTR mode and keep the key and IV secret.
Does keeping the IV secret together with the key increase strength of encryption?
- 877
5
votes
1
answer
294
views
Stream Cipher Key Stream from Successive Hashes
I'm currently studying crypto and wondered what would be wrong with the following process...
I want to encrypt a long message $M$ with a short symmetric key $K$ and a public nonce $X$.
The idea is to ...
- 53
3
votes
2
answers
2k
views
Proper use of AES CTR
I've read that AES CTR is only safe if used properly. Therefore, I want to be sure that I use it properly.
The initial vector (IV) can only be used once, it doesn't have to be random. Is it secure to ...
- 33
0
votes
2
answers
753
views
Encryption algorithm multiple threads/cores for higher throughput
There are situations where a single connection (or file) may require additional throughput available. While network bandwidth and CPU cores are available, they cannot be utilised. (Aside from means ...
- 147
1
vote
2
answers
505
views
Why is possible to encrypt multiple messages within the same stream in AES
I have a standard random key and IV. Then I am creating a cipher using these keys and iv and then encrypt a specific message. Later on, if I try to encrypt another message with the same cipher(which ...
user96631
3
votes
1
answer
1k
views
What is the maximum number of messages that can be encrypted using the same key for CTR mode?
In the counter mode of encryption, the nonce cannot be used again unless a new block cipher key is chosen. What is the maximum number of messages that can be encrypted using the same key?
The maximum ...
- 43
2
votes
3
answers
1k
views
What does counter mean in Counter (CTR) Mode? Is it the same as nonce?
As asked above, what does "counter" mean exactly? Is it the same as nonce?
Also, the book Network Security Essentials (6ed.) from William Stallings states, "Typically the counter is ...
