Breaking Bitcoin: ECDSA vs XMSS Bitcoin relies on several algorithms to secure the coin from theft. Prominent among these is the Elliptic Curve Digital Signature Algorithm (ECDSA). An ECDSA employs asymmetric encryption to generate public/private key pairs (what crypto users employ to send and receive coins). Consequently, a classical computer will require at least 10 billion years’ worth of brute-force computing time to derive a private key from a public key. The advent of quantum computing, however, suggests that this encryption safeguard may soon be broken. Unlike the public cryptosystem RSA, the math behind an elliptic curve algorithm is fairly complex.