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Oct
23
comment How does one use AES block cipher modes of operation?
Well, about the key. Actually, in my design, I have not to care about how data will be transfered, if you mean this. I have to implement a mechanism which just en/de-crypts data. All these about senting and receiving data are for me, to understand how the system should work. But, as usual, I have another question. How much time mediates between two messages. Furthermore, which should be an acceptable delay time for decrypter to receive a new message. As I think, this time should be 1-2 cc, so the users don't have restriction on when to send each new message.
Oct
21
comment How does one use AES block cipher modes of operation?
If both encryptor and decryptor have the same initial value, at 1st counter, and the mechanism to increase this value, then it's easy for someone to decrypt every message. On the other hand, if the transmitter has to sent every counters' value to recipient, i think it's also simple for someone to decrypt every message. So, what do I forget?
Oct
21
comment How does one use AES block cipher modes of operation?
Ok until here. First, I have to tell you that my project has as reference NIST SP 800-38A. So, everything else than the 5 modes which described there is useless for me, but informative and nice for general knowledge. So thank you for your help and your time to answer every sily of my questions. And now i want a clarifiation in something you answered above. In CTR mode, I have to sent every counter's value to the recipient? Also, every time the en/de-cryption engine is started, the initial value must be standard or a random value by a generator? But here is where i'm confused.
Oct
16
comment How does one use AES block cipher modes of operation?
I have another question. Let's assume that i have one block cipher which receives 8bit every clk cyc. It needs 16 clk cyc to get a full input block. Encryption is running for 250 clk cyc and after that it needs 16 clk cyc to write out the encrypted block. So the total processing, from receiving the plaintext to write out the ciphertext,lasts 282 clk cyc. In which clk cyc can the same block starts receiving a new plaintext? In my opinion (but i don't know if i am right), this will happend at the 266th clk cyc. What do you say?
Oct
11
awarded  Commentator
Oct
11
comment How does one use AES block cipher modes of operation?
2)I encrypt a plaintext with a mode using an IV and send the ciphertext to you. How will you decrypt the message? With a new IV which generated on your decoder, or I have to sent you the IV too? Respectively, in CTR mode, what happend with the counters? Both in encryptor and decryptor, counters must begin counting from the same initial value?
Oct
11
comment How does one use AES block cipher modes of operation?
Thank you my friend. It's reality that i didn't put my question forward. But it helped me understand the topic better. It'd be nice if you could explain in more detail the second part of your answer. Also, I have two more questions: 1)According to NIST's publication, there are some block cipher modes. Can I modify someway these modes to work in parallel. (just a yes/no, if there is a solution, i'd like to think on my own)
Oct
11
awarded  Scholar
Oct
11
accepted How does one use AES block cipher modes of operation?
Oct
11
awarded  Supporter
Oct
8
comment How does one use AES block cipher modes of operation?
i think that i have a component (i don't care how it is made) which "apply" (i don't know if it's correct to say this) the AES algorithm in 8 bit.
Oct
8
asked How does one use AES block cipher modes of operation?
Oct
8
comment AES block cipher modes of operation
thank you for your answer. i tried to refine the 2 point of my question in a new question. I think i make a point of what i mean.
Oct
8
awarded  Student
Oct
8
comment AES block cipher modes of operation
At least, i learned how to write the word "right"!!!! Sorry for my english. So, am i right about 10 clock pulses when we use a 128 bit key?
Oct
8
comment AES block cipher modes of operation
If I'm not wrong, every block cipher needs 10 cycle rounds to encrypt input's data. So, as i understand, that block cipher can't "receive" a new plaintext for 10 cycle rounds. And by cycle round i understand clock pulses. Am I wright?
Oct
8
comment AES block cipher modes of operation
And for my second question, I mean "block cipher"
Oct
8
comment AES block cipher modes of operation
So, for my first question, the data input's size depending on the key size?
Oct
8
asked AES block cipher modes of operation