[New BIP]: Universal Addresses

Summary:

This proposal suggests a new Bitcoin Improvement Proposal (BIP) for universal, multi-currency addresses that are not specific to any cryptocurrency. The proposed address format provides strong cryptographic security while maintaining the level of transactional privacy specific to each underlying currency. BIP32 derivation allows compatibility with existing HD wallets, while BIP44 numberings at the coin-selection level allow new coins to be used with the same Universal Addresses.The use of BIP32 extended public key nodes as a Universal Address format is suggested. Derivation path levels for Universal Addresses, serialization format, and URL-style query parameters for denotability of recipient-specified currency acceptance preferences have been discussed in detail. This proposal recommends using the same base58 format as current extended public keys for interoperability with existing software and suggests substituting the 32-bit “parent key fingerprint” and “child number” with 0x00000000 for additional privacy.Universal Addresses have two possible security models: they can be fully public or kept secret between the recipient and exactly one sender. Fully private addresses, where the recipient allocates a new address for every sender, are secure and have other benefits but other security models have inherent weaknesses and should definitely be avoided.The Universal Address format allows users to share one address and accept various cryptocurrencies in the same wallet, eliminating the need for multiple addresses. Transactions can be made using single-use addressing, with multi-transactional payments providing better privacy as it does not permit correlation of outputs to any single user. When sender wallets support "Enhanced Privacy Mode," a substantial gain in transactional privacy is obtained by the use of Universal Addresses.The proposed BIP, Universal Addresses, allows for a single address to be used across multiple cryptocurrencies and projects. It includes guidelines for wallets implementing this system and how to handle split transaction payments. Privacy concerns are addressed, with the onus placed on senders to protect their own privacy. Recipients should only share non-public Universal Addresses with one sender to limit the impact of any disclosures.The Bitcoin Improvement Proposal (BIP) ${BIPNUM} suggests a Universal Address format for wallets to use when receiving cryptocurrency payments. Wallets that support Universal Addresses should show a list of currencies in its user interface that correspond to the ones denoted by the appended “accept” URL-style query parameter. Three situations utilizing Universal Addresses are described in the context. The proposed BIP32 extended public key nodes as a Universal Address format is unlikely to cause confusion, and version bytes are maintained for backwards-compatibility with BIP32. While some existing or future projects may be incompatible with this BIP, its benefits to users and the cryptocurrency ecosystem should not be underestimated.

Updated on: 2023-05-20T21:25:43.058258+00:00