Generate a key for AES
aes, encryption, java
Solution
A strong AES key will be 16, 24, or 32 bytes long. If you restrict the key to bytes that map to printable US-ASCII characters, the key will be weaker than expected, because its range is limited (to about 100 bits, rather than 128—many millions of times weaker). It would be better to use an encoding like hexadecimal, base-64 or base-85 to represent the key as text; of course, these representations will be longer.
To create a secure key, use a `KeyGenerator` that is based on a properly seeded cryptographic random number generator; providers will choose their own RNG if you don't specify one:
KeyGenerator gen = KeyGenerator.getInstance("AES");
gen.init(128); /* 128-bit AES */
SecretKey secret = gen.generateKey();
byte[] binary = secret.getEncoded();
String text = String.format("%032X", new BigInteger(+1, binary));
System.out.println(text);
If you want, you can instantiate your own `SecureRandom` instance, using your preferred algorithm and provider, and pass it to the key generator via an overload of the `init()` method.
There are key derivation methods that attempt to mitigate the weaknesses of password-based keys, but a password-based key will always be more predictable.
Problem
I found this on the internet: http://www.code2learn.com/2011/06/encryption-and-decryption-of-data-using.html Basicly, what I want to do is instead of having the key set like ``` new byte[] { 'T', 'h', 'e', 'B', 'e', 's', 't', 'S', 'e', 'c', 'r','e', 't', 'K', 'e', 'y' }; ``` I want it to be random(but must be 16 bytes), and to have access to it(print it on the screen). Also, is there a way to set it as a string, instead of byte type?