Local encryption for single sign-on

Abstract

The present disclosure describes techniques that allow for a client-side application, located on a first client device, to generate a random encryption key and encrypt locally-stored application data with the random encryption key. In order to ensure that the client-device application is unable to decrypt the locally-stored encrypted application data prior to authenticating with an external authentication source (i.e., SSO, IdP), the client-side application divides the random encryption key into at least a first share and a second share according to a secret sharing algorithm. The first share is transmitted to a trusted third party, while the second share is encrypted locally and stored in a secure location on the client device. Upon successful authentication, the trusted third party returns the second share to the first client device. The client-side application derives the random encryption key and decrypts the locally-stored encrypted application data to be used by the client-side application. By dividing the key used to encrypt the client-side application data and storing one of the secret shares necessary to deriving the key at a trusted third party, the present disclosure solves the problem of how to encrypt local application data when the login credentials for the application are managed by a trusted third party, such as an SSO system.