Abstract: Various methods are provided for secure two-factor authentication, and more specifically, for incorporating a layer of security to two-factor authentication using Short Message Service in a manner virtually transparent to the end-user. Methods may include receiving a request for registration for two-factor authentication from a client including a username and password; providing a request for a mobile device number; receiving the mobile device number and a pre-shared key; sending to a mobile device an identity of the client and a server key share; receiving from the mobile device a mobile device key share; sending information corresponding to an exchange with the mobile device and a challenge derived from the pre-shared key to the client in response to the device key share corresponding to the server key share; receiving confirmation of registration with the mobile device; and establishing a shared key in response to verification of the confirmation.

Abstract: Systems and methods for call authentication are provided. A method can include an enrollment protocol that ensures users control the number they claim to own, a handshake protocol that mutually authenticates the calling parties, and a call integrity protocol that ensures the security of the voice channel and the content it carries. A server can act as either an endpoint or intermediary between user clients and client-server architecture can be employed. All protocols can include end-to-end cryptography and the enrollment protocol can issue a certificate that binds the identity of the client to a phone number.

Abstract: Systems and methods for call authentication are provided. A method can include an enrollment protocol that ensures users control the number they claim to own, a handshake protocol that mutually authenticates the calling parties, and a call integrity protocol that ensures the security of the voice channel and the content it carries. A server can act as either an endpoint or intermediary between user clients and client-server architecture can be employed. All protocols can include end-to-end cryptography and the enrollment protocol can issue a certificate that binds the identity of the client to a phone number.