Forget invisible ink, how about super-secret ink? Scientists have successfully hidden a 256-bit cipher key within molecules of ink on a handwritten letter.

AES stands for Advanced Encryption Standard, and the "256" in AES-256 refers to the length of the encryption key, which consists of 256 bits.

Medicine show: Crown Sterling demos 256-bit RSA key-cracking at private event Demo of crypto-cracking algorithm fails to convince experts.

Both Cipher RAID storage solutions come integrated with bullet proof, highly secure AES 256-bit full disk hardware encryption that is simple to use.

This security capability is based on the industry’s leading Trusted Computing Group’s Opal standard and features stronger 256-bit Advanced Encryption Standard (AES) keys.

First of all there are only 26 keys. You might have heard of people talking about 128-bit keys or 256-bit keys, well this is a 5 bit key (i.e. 26 in binary is 11010).

If a quantum system had to crack a 256-bit key, it would take about as much time as a conventional computer needs to crack a 128-bit key. A quantum computer could crack a cipher that uses the RSA ...

DES was considered unbreakable in the 1970s except by brute-force attack — that is, trying every possible key (DES uses a 56-bit key, so there are 256, or 72,057,594,037,927,936 of them).