Work out ecc key strength instantly with clear inputs, formula shown and shareable results.
Elliptic-curve security is about half the field size because Pollard's rho solves the discrete logarithm in roughly sqrt(n) group operations. P-256 therefore delivers 128-bit security in a 256-bit key, matching RSA 3072 while being far cheaper to compute and carrying far smaller certificates and signatures.
ECC strength
security bits ~ field size / 2; RSA equivalent from NIST SP 800-57 (ECC 256 ~ RSA 3072, ECC 384 ~ RSA 7680)
It offers comparable security with a simpler, misuse-resistant design, deterministic signatures and no dependence on a random nonce per signature. Support is now broad but not universal in older hardware and TLS stacks.
It was chosen by Bitcoin for its efficient structure and verifiably non-random parameters. It offers the same 128-bit level as P-256 but is not in the standard TLS or PKI profiles.