IDENTITY AND CONTENT AUTHENTICATION FOR PHONE CALLS

• US 20180294959A1
• Filed: 03/30/2018
• Published: 10/11/2018
• Est. Priority Date: 04/05/2017
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Traynor, Patrick G., Reaves, Bradley G., Blue, Logan E., Vargas, Luis, Abdullah, Hadi, Shrimpton, Thomas
• Granted Patent: US 10,764,043 B2
• Time in Patent Office: Days
• CPC Class Codes: H04L 2209/80 Wireless network architectures or network communication protocols for wireless network security H04W12/00
• CPC Class Codes: H04L 63/0823 using certificates cryptographic mechanisms or cryptographic arrangements for entity authentication involving certificates H04L9/3263
• CPC Class Codes: H04L 65/1076 Screening of IP real time communications, e.g. spam over Internet telephony [SPIT]
• CPC Class Codes: H04L 9/0844 with user authentication or key authentication, e.g. ElGamal, MTI, MQV-Menezes-Qu-Vanstone protocol or Diffie-Hellman protocols using implicitly-certified keys
• CPC Class Codes: H04L 9/3242 involving keyed hash functions, e.g. message authentication codes [MACs], CBC-MAC or HMAC
• CPC Class Codes: H04L 9/3263 involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823
• CPC Class Codes: H04L 9/3268 using certificate validation, registration, distribution or revocation, e.g. certificate revocation list [CRL]
• CPC Class Codes: H04W 12/04 Key management, e.g. using generic bootstrapping architecture [GBA]
• CPC Class Codes: H04W 12/0431 Key distribution or pre-distribution; Key agreement
• CPC Class Codes: H04W 12/06 Authentication
• CPC Class Codes: H04W 12/069 using certificates or pre-shared keys
• CPC Class Codes: H04W 12/106 Packet or message integrity
• CPC Class Codes: H04W 12/48 using secure binding, e.g. securely binding identity modules to devices, services or applications

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.

Claims

1. A method for call authentication comprising:

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.

2. The method according to claim 1, wherein a server acts as either an endpoint or intermediary between user clients.

3. The method according to claim 1, wherein all of the protocols implement end-to-end cryptography.

4. The method according to claim 1, wherein the enrollment protocol issues a certificate that binds the identity of the client to a phone number.

5. The method according to claim 4, wherein the enrollment protocol includes:

establishing a client C and an enrollment server S;

(message

     1) C sending an enrollment request with S'"'"'s identity, C'"'"'s identity information, C'"'"'s phone number, and C'"'"'s public key;

(message

     2) S sending a nonce (NNet), the identities of C and S and the phone numbers of C and S with a timestamp to ensure freshness, liveness, and to provide a “

token”

for the particular authentication session;

(message

     3) S confirming that C controls the phone number it claims by S placing a call to C'"'"'s claimed phone number, and S transmitting a nonce over the voice channel when a call is answered;

(message

     4) C sending both N_Net and N_Audio along with the IDs of server, client, a timestamp, and a signature covering all other fields; and

(message

     5) S replying with a signed certificate issued to C.

6. The method according to claim 5, wherein the enrollment protocol includes an out-of-band process for verifying identity of certificates (particularly high-value certificates), authentication of supporting documentation, and/or CNAM3 lookpups.

7. The method according to claim 1, wherein the handshake protocol includes a first phase indicating to a server and the calling party that a call is imminent and a second phase of authenticating both parties on the call and establishing shared secrets.

8. The method according to claim 1, wherein the call integrity protocol includes exchanging content authentication information for the duration of the call using digests of call audio authenticated with HMACs.

9. A method of authentication, comprising:

performing an enrollment protocol between a client and a server to ensure that a user controls a phone number and to issue a certificate to the user;

performing a handshake protocol between two calling parties including a caller and a callee through the server to authenticate the two calling parties; and

performing a call integrity protocol to ensure security of a voice channel and a content it carries.

10. The method according to claim 9, wherein the certificate the enrollment protocol binds an identity of the client to the phone number.

11. The method according to claim 10, wherein the identity includes at least one of a name, an organization, and pertinent information.

12. The method according to claim 11, wherein the enrollment protocol comprises:

sending an enrollment request with the server'"'"'s identity, the client'"'"'s identity, the client'"'"'s phone number, and the client'"'"'s public key by the client;

sending a nonce N_Net, the identities of the client and the server, and the phone numbers of the client and the server with a timestamp by the server;

sending the nonce N_Net and an audio nonce N_Audio by the client; and

replying with a signed certificate issued to the client by the server.

13. The method according to claim 12, wherein the server provides a token during sending the nonce N_Net.

14. The method according to claim 9, wherein the handshake protocol comprises a first phase indicating imminent call between the server and the calling parties, and a second phase authenticating the calling parties.

15. The method according to claim 14, wherein the first phase comprises:

indicating by the caller to the server that the caller want to place a call;

informing by the server to the callee that an authenticated voice call is coming; and

informing by the server to the caller whether the callee is using the authenticated voice call.

16. The method according to claim 15, wherein the caller and the callee compute independently messages and send the messages in parallel during the second phase of the handshake protocol.

17. The method of according to claim 16, wherein the messages contain all information necessary for a Diffie-Hellman Key establishment authenticated with a signature key in a certificate of the caller and the callee.

18. The method of according to claim 9, wherein the call integrity protocol confirms that the voice channel is established and confirms when a call ends.

19. The method of according to claim 18, wherein the call integrity protocol comprises:

sending a message indicating that a voice call is complete, and including a timestamp and a hash message authentication code (HMAC) of the timestamp by the caller and the callee;

sending other audio digests by the caller and the callee after the voice call begins; and

sending a call concluded message containing a timestamp with an HMAC.

20. A method of authentication, comprising:

performing an enrollment protocol between a client and a server to ensure that a user controls a phone number and to issue a certificate to the user;

performing a handshake protocol between two calling parties including a caller and a callee through the server to authenticate the two calling parties; and

performing a call integrity protocol to ensure security of a voice channel and a content it carries,

wherein the enrollment protocol comprises;

sending an enrollment request with the server'"'"'s identity, the client'"'"'s identity information, the client'"'"'s phone number, and the client'"'"'s public key by the client;

sending a nonce N_Net, the identities of the client and the server, and the phone numbers of the client and the server with a timestamp by the server;

sending the nonce N_Net and an audio nonce N_Audio by the client; and

replying with a signed certificate issued to the client by the server,

wherein the handshake protocol comprises;

indicating by the caller to the server that the caller want to place a call;

informing by the server to the callee that an authenticated voice call is coming; and

informing by the server to the caller whether the callee is using the authenticated voice call, and

wherein the call integrity protocol comprises;

sending a message indicating that a voice call is complete, and including a timestamp and a hash message authentication code (HMAC) of the timestamp by the caller and the callee;

sending other audio digests by the caller and the callee after the voice call begins; and

sending a call concluded message containing a timestamp with an HMAC.