The number of the round in AES depends on the key size(128,192 and 256 bits) according to key size the security strength will be.

yes, but we know that is constant, or attacker has aware on number of rounds,

my opinion was, number of rounds dynamic between two numbers such as 1 to 16

one time it become 5 for example, and other time it one of numbers in 1 to 16.

so that attacker, could not guess number of rounds in encryption process. OK?

If it becomes dynamic, you will have two keys for the algorithm, one is the encryption key and the other is the number of rounds, yes the algorithm will be more secure and more complex to implement. However, in AES, the bruet force attack is not the problem. One of the problems that we encounter with symmetric encryption is key distribution, if now we have two keys, the complexity will be doubled. The number of rounds enhances the avalanche effect which enhances the security of the algorithm.

I agree with Mohammad zakaria Masoud

This proposal of dynamic rounds number will be very important when we will opérat quantics computers, but at the moment the existante RSA system is secure against several attacks.

OK, I think that RSA, slower than AES and other stream Cipher method, I assume that receiver has one secret key and other sent by Sender, we create only one key for receiver, after receiver construct from self privet key and received key, Generate dynamic round number.

also, we could use two key such as RSA, But change one of Stream Cipher Algorithm such as RC4, and send whole of data by key stream method.

with this method we have high security and speed.

I think totally the security of AES depends on key size because the attack of AES takes 1/2^keysize we cannot have more than this probability.

Ok, that's right, but, why AES could not extend length of key from 256 to bigger length?

T he number of rounds in AES is variable and depends on the length of the key. AES uses 10 rounds for 128-bit keys, 12 rounds for 192-bit keys and 14 rounds for 256-bit keys. Each of these rounds uses a different 128-bit round key, which is calculated from the original AES key. In case of increasing the key size larger than 256 such as 512bits we need higher number of round to get probability 1/2^512

in conclude, I understand number of rounds and length of keys are dependent with together. so, if I want propose new algorithm such as AES, must number of rounds and length of key size independent. OK?

I think the number of rounds and the key size are related in the sense that larger key size needs more number of rounds to give attacking probability 1/2^keysize for AES.

OK, Dear Dr.Zeyad Mohammad

very tank you for contribution in this discussion and for good recommendtions.

in fact some of my basic and fundamental problems solved by your good guidance, I hope to, as soon as we work in common project with together.

best regards

mohammad zeynali

also, very thank for other researchers and readers that contribute in this Discussion.

Dear Mohammad Zeynali

My pleasure to contribute with you in the future and welcome.

Hi

the number of rounds in AES encryption, must be static, because the number of rounds depend on the length of the key, the machine implementation, and if the machine works on the 512 bits , then we can extended the number of the rounds, but one important of the security of AES depend on the size of the key ( no number of rounds),

please see RC5, and RC6 this encryption system with variable rounds.

best regards

Hi,

The number of round may affect the computation power due to its process to deal with the key requirements.While, the security strength of AES depend on the size of the key ( It is not on the number of rounds).

Regards