AES encrypt/decrypt with Bouncy Castle provider [duplicate]

Answer 1

You would either use

Security.addProvider(new BouncyCastleProvider());
Cipher cipher = Cipher.getInstance("AES", "BC");

or else

Cipher cipher = Cipher.getInstance("AES", new BouncyCastleProvider());

That said, Cipher.getInstance("AES") uses Electronic Codebook, which is insecure. You either want Cipher Block Chaining (Cipher.getInstance("AES/CBC/PKCS5Padding")) or Counter (Cipher.getInstance("AES/CTR/NoPadding")) modes; they are both secure, the primary difference being that CBC requires padding while CTR does not.