Combined authentication and encryption
View Patent ↗A system and methods are provided for establishing an authenticated and encrypted communication connection between two devices with at most two round-trip communications. During establishment of an initial authenticated, encrypted communication connection (or afterward), a first device (e.g., a server) provides the second device (e.g., a client) with a token (e.g., a challenge) that lives or persists beyond the current connection. After that connection is terminated and the second device initiates a new connection, it uses the token as part of the handshaking process to reduce the necessary round-trip communications to one.
1. A method comprising:
providing a device with a first unsolicited token during an authenticated first communication connection;
terminating the first authenticated communication connection;
receiving encrypted authentication data from the device;
generating a session key from the first unsolicited token;
determining whether the encrypted authentication data decryptable with the session key;
acknowledging to the device establishment of a second communication connection as a response to the receiving of the encrypted authentication data, if the encrypted authentication data decryptable with the session key; and
providing the device with a second token if the encrypted authentication data not decryptable with the session key.
2. The method of claim 1 , further comprising:
receiving from the device new encrypted authentication data;
generating a new session key from the second token;
decrypting the new encrypted authentication data with the new session key; and
acknowledging to the device establishment of a second communication connection.
3. The method of claim 1 , wherein the authentication data comprises:
an identifier of a user of the device;
the first unsolicited token or the second token; and
device-specific data.
4. The method of claim 3 , wherein the authentication data further comprises a timestamp.
5. The method of claim 3 , wherein the identifier of the user of the device is a telephone number associated with the user.
6. The method of claim 3 , wherein the device-specific data is a user agent operating on a second device.
7. The method of claim 3 , wherein the token is one of the first unsolicited token or the second token.
8. The method of claim 6 , wherein generating the session key comprises applying a function to the first unsolicited token and to a secret shared between a first device and the second device.
9. The method of claim 8 , wherein shared secret is a password to an application hosted by the first device and executed on the second device.
10. A non-transitory computer readable medium storing instructions that, when executed by one or more processors, cause the one or more processors to:
provide a device with a first unsolicited persistent challenge before termination of a first authenticated communication connection with the device; and
establish a second communication connection with the device after termination of the first authenticated communication connection;
receive a set of encrypted authentication data generated by the device based in part on the first unsolicited persistent challenge and a shared secret that is shared by the device and an authenticating device; and
transmit an acknowledgement of the second communication connection in response to receiving the set of encrypted authentication data.
11. The non-transitory computer readable medium of claim 10 , further storing instructions for, after receipt of the set of encrypted authentication data:
generating a session key based in part on the first unsolicited persistent challenge and the shared secret;
decrypting the set of encrypted authentication data with the session key; and
parsing the set of decrypted authentication data to verify its content.
12. The non-transitory computer readable medium of claim 11 , wherein the content of the set of decrypted authentication data includes:
a user identifier of a user of the device; and
the first unsolicited persistent challenge.
13. The non-transitory computer readable medium of claim 12 , wherein the shared secret is a password for an application executed on a second device and hosted by a first device.
14. A system comprising:
a processor; and
memory configured to store instructions that, when executed by the processor, cause the system to:
provide a client device with a first unsolicited temporary challenge during a first authenticated connection with the client device;
receive a set of authentication data encrypted with a key generated from the first unsolicited temporary challenge after termination of the first authenticated connection;
generate a session key based in part on the first unsolicited temporary challenge and a shared secret that is shared with the client device;
if encrypted authentication data decryptable with the session key, acknowledge establishment of a second connection with the client device in response to receiving the set of authentication data; and
providing the device with a second token if the encrypted authentication data not decryptable with the session key.
15. The system of claim 14 , wherein: the shared secret is a password for an application executed on the client device and hosted by the system; and
the set of authentication data comprises a telephone number associated with the client device.
16. The system of claim 14 , wherein the memory is further configured to store instructions that, when executed by the processor, cause the system to:
when the set of authentication data not decryptable with the session key:
provide the client device with a new challenge;
receive a new set of authentication data encrypted with a new key generated from the new challenge;
generate a new session key based in part on the new challenge and the secret shared with the client device;
decrypt new encrypted authentication data with the new session key;
parse decrypted authentication data to authenticate the client device; and
acknowledge establishment of the second connection with the client device.
17. The system of claim 14 , wherein the authentication data comprises:
an identifier of a user of the client device;
a token associated with the first unsolicited temporary challenge; and
device-specific data.
18. The system of claim 17 , wherein the authentication data further comprises:
a timestamp.
19. The system of claim 17 , wherein the user identifier is a telephone number of the user, or a user agent operating on the client device.
20. The system of claim 14 , wherein generation of the session key comprises application of a function to a first token associated with the first unsolicited temporary challenge and to a secret shared with the client device, wherein the shared secret is a password to an application executed on the client device.