Great question, mate! PGP and Bitcoin use different types of public key cryptography.

PGP typically uses RSA, a cryptosystem based on the difficulty of factoring large numbers. It's solid for encrypting messages and signing digital data.

Bitcoin, on the other hand, uses ECDSA over the secp256k1 curve. This relies more on the math of elliptic curves - it's efficient and fits well with Bitcoin's goals (like generating addresses from public keys).

So while both are forms of public key crypto, they're quite different under the hood!