PayNym

A PayNym is a memorable, shareable handle layered on top of a BIP47 payment code. Because a raw payment code is a long, opaque string, a PayNym hashes that code into a unique fingerprint that produces both a readable name (for example +SilentSatoshi) and a deterministic robot avatar. The friendly identifier maps one-to-one to the underlying cryptographic code, so users can recognise and verify a counterparty at a glance without copying error-prone key material.

From handle to private payment

Under the hood a PayNym is still a BIP47 payment code, so paying one inherits all of that standard's privacy properties. The first payment to a never-before-seen PayNym triggers a one-time notification transaction carrying the sender's blinded code; afterwards both wallets derive a fresh, unlinkable address for every subsequent payment using their shared ECDH secret. No static address is ever posted publicly, so a payer cannot scrape the recipient's balance or history.

Why it matters for sovereignty

PayNyms popularised reusable payment codes by solving a usability gap: a sovereign Bitcoiner can publish a single nym on a profile or donation page and accept unlimited payments without address reuse. That preserves fungibility and frustrates the wallet-clustering heuristics that chain-analysis firms rely on. The concept originated in self-custodial wallet tooling and remains directory-backed so handles can be looked up and resolved to their codes.

The cryptographic primitive a PayNym wraps is the payment code (BIP47), and the handshake that activates it is the notification transaction.