Address

Behind every crypto address sits a chain of cryptography, not a bank clerk assigning account numbers. The address is generated from a public key, which is itself derived from a private key using elliptic-curve math. Bitcoin then runs that public key through one or more hashing functions and adds a checksum, producing a shorter, error-checked string that is safe to publish. Ethereum and other EVM chains take a simpler route: the address is the last 40 hex characters of the hashed public key, prefixed with "0x".

Address formats have evolved for different reasons. Bitcoin has moved through several versions: legacy addresses starting with "1", script-based addresses starting with "3", SegWit addresses starting with "bc1q", and Taproot addresses starting with "bc1p", each improving privacy, fee efficiency, or typo protection. Ethereum instead uses a single format, secured by a mixed-case checksum (EIP-55) that flags most single-character mistakes.

Because an address is public by design, it can be shared freely to receive funds without exposing the private key needed to spend them. That separation is the core of self-custody. It also means addresses are pseudonymous rather than anonymous: every transaction tied to an address is permanently visible on the blockchain, so patterns of activity can sometimes be linked back to a real identity.

A common and costly mistake is sending funds to an address on the wrong network, since a valid-looking address on one chain may not exist, or may belong to someone else, on another.