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### 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 ...
16 views

### Use HMAC for every block encryption operation [duplicate]

Is it possible to use HMAC while performing encryption of blocks? I think that the main problem with the approach would be to get the same output size as the block, from the HMAC function. Also, the ...
239 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 ...
141 views

### Do some Block Cipher Modes encrypt the nonce and then XOR it with the data?

Reading https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation#Counter_(CTR) it looks like CTR (and some other modes) encrypt the nonce (plus count, for CTR) rather than the plaintext. The ...
37 views

### Equivalent keys in Hash Functions

Let's suppose I want to use a (keyed) hash function as a stream cipher, I provide a key and a message to be hashed as a counter (like a nonce), and so, XOR each hashed output block on the plaintext. ...
40 views

### Hashing function as a cipher in CTR mode [duplicate]

Can we use hashing function in CTR mode as a cipher? And our key could be a random initialization vector. Are there any practical problems with that idea, that we don't do this?
207 views

### Secure AES IV with static salt

I have an (offline) shared secret key (symmetric) which is used to encrypt/decrypt data. Now this data belongs to a specific user which is known on the backend and frontend. My idea was to use the ...
119 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 ...
133 views

### How much data can we encrypt using AES 256 before changing the key?

Although this question has been answered in this link (After How Much Data Encryption (AES-256) we should change key?), I am not satisfied with the answers because the Recommendation for Block Cipher ...
140 views

### CTR block generation

From what I understand, CTR works by taking a counter, concatenating it with a nonce, and encrypting the result, which gets XORed to the ciphertext. For a 128-bit block cipher (ie. AES), my ...
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### Is Paillier a stream or block encryption

Does Paillier follow a stream encryption or block encryption technique. If it’s a block encryption then what is the size of the block in bits or bytes.
641 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 ...
176 views

### With AES-CTR does the block input need to be implemented as nonce || counter?

I am looking at an AES-CTR implementation (WebCrypto) and it takes an initialization parameter count which is an array of 16 bytes. It then asks you to specify <...
Let ssuppose that we are using AES in CTR mode to encrypt a number of blocks ($x$ bytes each). How is the current used IV (nonce+ctr) synchronized among both communicating entities? I suppose that the ...
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 ...