Bitcoin uses ECDSA.
This.
ECDSA was picked for Bitcoin
because it has much shorter keylengths than other digital signing scheme/crypto schemes. For instance, all the following keylengths are approximately equal in terms of mathematical entropy:
--3,072-bit RSA key
--256-bit ECDSA key
--128-bit AES key
There is no doubt that an AES 128 key is sufficient protection, probably for decades, if not longer (protection against well-funded attacker with a billion dollars of computing resources)