Abstract: A system and method for encrypted and authenticated electronic messaging using a central address book is disclosed herein. In some embodiments, a system for encrypted and authenticated electronic messaging includes a computer system for electronic communication between a sender client and a recipient client, a central address book, and an encrypted message. The central address book includes for each user an alias, a public key, and an address encoded with the public key. The computer system automatically electronically transmits the central address book to each user of the central address book when updated. The encrypted message includes a recipient alias, a recipient public key, and a recipient address encoded with the recipient public key. The recipient public key and the recipient address encoded with the recipient public key are used by the sender client to authenticate the recipient to the sender.