New answers tagged stream-cipher
The RC4 stream cipher does not mix the data into the key stream. The key stream it generates only depends on the secret key with which it was initialized. And "corruption", that means "flipped bits in the ciphertext" will result in "flipped bits in the cleartext" after decryption, even in exactly the same positions, as in the ciphertext, so classical ...
If a large file enciphered using RC4 is partially corrupted, the uncorrupted portions remains fully decipherable, including what's after a corrupted portion if the corruption modifies this data's value, but not its length (a length corruption could occur e.g. for serial communication, but is unlikely on a hard disk). This is a property of all stream ciphers. ...
In your case I'd recommend you to try TripleDES, maybe with a paired ARM MCU - it's cheap and fast enough... Try to take a look at STM chips, I used them before and I have a very good recommendations due to price/perfomance. Also you can try to implement DES physically if you have a hi-speed requirement in your device's spec list.
Use AES-128, the instruction set in most CPU's (AES-NI) speeds up the encryption and does not put to much load on your CPU. I would use CBC but there might be better mode operations for encrypting files. Also don't forget to use a MAC. Using a one time pad (OTP) is nice but what you're doing is not an OTP it's more a Vigenère cipher. If you were to use OTP ...
Top 50 recent answers are included