Abstract: Systems and methods for managing private and public encryption keys without the need for a third party certification authority. An initial value is generated by an authentication server. The initial value is divided into at least two portions and each portion is communicated with a user using different communication channels. The user receives the portions and enters a secret string value (i.e. a secret sentence) known only to the user. The portions are concatenated together to recreate the initial value. The portions, the initial value, and the secret string value are then used to create public and private keys for use by the user. Any recipient can authenticate digital signatures without needing the secret string value or the user's device can authenticate a digital signature using the portions and the secret string value.