Public Key / Address

A public key is the cryptographic counterpart to a private key, and a wallet address is the shorter, more shareable string most wallets actually derive from it and display for sending or receiving funds.

Every crypto wallet is built on a matched pair: a private key that stays secret and a public key that's mathematically derived from it but can't be used to work backward to the private key. Most blockchains then run that public key through one or more hashing steps to produce something shorter and easier to handle — the wallet address you actually see, copy, and share. On some networks the terms get used almost interchangeably in casual conversation, but the distinction matters technically: a public key is used to cryptographically verify a signature came from the matching private key, while the address is the practical, everyday identifier tied to that key pair. Both are safe to share freely. Unlike a private key, publishing a public key or address publicly gives an attacker nothing usable to spend funds — the whole design of public-key cryptography rests on that asymmetry, verification without secrecy.

This matters directly when swapping crypto because the address is the one piece of information you're responsible for getting exactly right on every transaction. There's no equivalent of a bank double-checking a routing number for you — a blockchain simply executes the instruction it's given, so a wallet address wrong by even a single character can mean funds sent to nobody, or worse, to someone else's genuine address. That's also why the receiving side of a swap deserves the same care as the private key stays hidden on the sending side: the address has to be copied fresh from a trusted source, not retyped from memory or reused carelessly from old transaction history, since address-lookalike scams like address poisoning specifically exploit that habit.

On Zest, every swap displays the destination address it will send funds to before you confirm, exactly as entered — the interface never substitutes or auto-fills a different address behind the scenes. Some networks pair that address with an additional memo or destination tag, and both pieces need to match exactly for funds to land correctly. For a fuller walkthrough of double-checking every field before sending, see the verify a crypto transaction guide.

Because a wallet address is just a derived, shareable form of a public key, it carries none of the risk a private key does — you can post it, hand it to a merchant, or paste it into an exchange order without any loss of security, which is precisely what makes non-custodial swapping practical: an exchange partner only ever needs to know where to send the result, never who controls it.