On 2018-01-02 02:35 PM, Pascal Hambourg wrote:
Le 02/01/2018 à 02:29, microsoft gaofei a écrit :
So AES is very lightweight ? I thought cryptography takes very much
space , but I saw 1MB space is plenty for AES
What are you talking about ? Where did you see this ? It does not make
sense. Encryption does not require extra space (except for header and
block padding). Encrypted data have the same size of cleartext data.
Encryption is similar in concept to compression. It could even reduce
the space requirements.
Encryption and compression both work by replacing strings of letters
with something else. What we call clear text, for example, is just a
Caesar cipher where each letter is replaced by a number (its ASCII code
or unicode). Morse code, on the other hand, replaces common letters with
shorter sequences of dots and dashes than less common letters.