Handshake is a decentralized naming protocol for allocating ownership rights to Top Level Domains (TLD), such as a .com or a .org, which one can use for websites, email addresses, or crypto addresses. Handshake users can purchase the rights to a TLD through an auction system, where participants submit bids in the form of HNS tokens. The winning bidder then registers the TLD under their cryptographic keys by entering the pair into Handshake's Proof-of-Work (PoW) blockchain, which acts as a distributed alternative to Certificate Authorities (CAs).