Radio authentication as root of trust for transport layer security

1 . A converged radio device comprising:

a radio-frequency (RF) transmitter system configured to perform communication in an internet protocol (IP) based network; and

an electronic processor configured to authenticate with a switching and management infrastructure (SwMI) of a second network of a different modality than the IP-based network by

establishing an unauthenticated secure IP session with a proxy server associated with the SwMI,

computing data derived from a certificate received from the proxy server during establishment of the secure IP session,

receiving, via the proxy server, a first authentication challenge from the SwMI,

determining a result of the first authentication challenge based on the data derived from the certificate,

transmitting a first response to the SwMI via the proxy server, the first response including a second authentication challenge and the result of the first authentication challenge,

receiving, from the SwMI via the proxy server, a second response including a result of the second authentication challenge and an indication that the result of the first authentication challenge matches an expected result of the first authentication challenge,

authenticating the SwMI by verifying that the result of the second authentication challenge matches an expected result of the second authentication challenge, and

responsive to authenticating the SwMI, performing communication in the second network via the proxy server.

2 . The converged radio device of claim 1 , wherein

determining the result of the first authentication challenge includes computing a modified value based on a base value received or generated by the converged radio device during authentication with the SwMI and the data derived from the certificate.

3 . The converged radio device of claim 2 , wherein the electronic processor is configured to compute the modified value according to a hash function of the base value and the data derived from the certificate.

4 . The converged radio device of claim 2 , wherein

the first authentication challenge includes a random number and a random seed RS used for generating the random number, and

the modified value is a modified random number based on the random number and the data derived from the certificate.

5 . The converged radio device of claim 2 , wherein

the first authentication challenge includes a random seed RS, and

determining the result of the first authentication challenge further includes

computing a session key KS based on the random seed RS and a shared key K, and

computing the result of the first authentication challenge according to a function of the modified value and the session key KS.

6 . The converged radio device of claim 5 , wherein the second network is a land mobile radio (LMR) TETRA network, and the electronic processor is configured to compute the session key KS using a first TETRA algorithm, and the function of the modified value and the session key KS is a second TETRA algorithm.

7 . The converged radio device of claim 1 , wherein verifying that the result of the second authentication challenge matches an expected result of the second authentication challenge includes

computing the expected result of the second authentication challenge based on the data derived from the certificate, and

determining that the result of the second authentication challenge matches the expected result of the second authentication challenge.

8 . A system for a switching and management infrastructure (SwMI) of a LMR network, the system comprising:

an electronic processor configured to authenticate a mobile station (MS) to the SwMI by

receiving, from the MS via a proxy server associated with the SwMI, a request to register to the LMR network,

transmitting, to the MS via the proxy server, a first authentication challenge,

receiving, from the MS via the proxy server, a first response including a second authentication challenge and a result of the first authentication challenge,

authenticating the MS by verifying that the result of the first authentication challenge matches an expected result of the first authentication challenge,

determining a result of the second authentication challenge based on data derived from a certificate received from the proxy server,

transmitting a second response to the MS via the proxy server, the second response including the result of the second authentication challenge and an indication that the result of the first authentication challenge matches an expected result of the first authentication challenge,

responsive to receiving, from the MS via the proxy server, an indication that the result of the second authentication challenge matches an expected result of the second authentication challenge, enabling communication by the MS in the LMR network via the proxy server.

9 . The system of claim 8 , wherein

determining the result of the second authentication challenge includes computing a modified value based on a base value received or generated by the SwMI during authentication with the MS and the data derived from the certificate.

10 . The system of claim 9 , wherein

the second authentication challenge includes a random number, and

the modified value is a modified random number based on a hash function of the random number and the data derived from the certificate.

11 . The system of claim 9 , wherein determining the result of the first authentication challenge further includes

computing a session key KS′ based on a random seed RS and a shared key K, and

computing the result of the second authentication challenge according to a function of the modified value and the session key KS′.

12 . The system of claim 11 , wherein the LMR network is a TETRA network, and the electronic processor is configured to compute the session key KS′ using a first TETRA algorithm, and the function of the modified value and the session key KS′ is a second TETRA algorithm.

13 . The system of claim 8 , wherein verifying that the result of the first authentication challenge matches an expected result of the first authentication challenge includes

computing the expected result of the first authentication challenge based on the data derived from the certificate, and

determining that the result of the first authentication challenge matches the expected result of the second authentication challenge.

14 . A method for mutually authenticating a LMR Mobile Station (MS) with a switching and management infrastructure (SwMI) of a LMR network, the method comprising:

establishing, with the MS, a secure internet protocol (IP) session with a proxy server associated with the SwMI;

receiving, with the MS via the proxy server, a first authentication challenge from the SwMI;

determining, with the MS, a result of the first authentication challenge based on first data derived from a certificate received from the proxy server during establishment of the secure IP session;

authenticating the MS by verifying, with the SwMI, that the result of the first authentication challenge matches an expected result of the first authentication challenge;

transmitting, with the MS, a second authentication challenge to the SwMI via the proxy server;

determining, with the SwMI, a result of the second authentication challenge based on second data derived from a certificate known to be from the proxy server;

authenticating the SwMI by verifying, with the MS, that the result of the second authentication challenge matches an expected result of the second authentication challenge; and

responsive to mutual authentication of the SwMI and the MS, performing communication, with the MS, in the LMR network via the proxy server.

15 . The method of claim 14 , further comprising:

responsive to mutual authentication of the SwMI and the MS, storing in a memory associated with the MS, information related to the certificate received from the proxy server; and

using the information related to the certificate received from the proxy server during authentication in a subsequent secure IP session with the proxy server.

16 . The method of claim 14 , wherein the method further comprises:

responsive to mutual authentication of the SwMI and the MS, transmitting, with the MS, a certificate signing request (CSR) to the proxy server.

17 . The method of claim 14 , wherein the secure IP session is a TLS session.

18 . The method of claim 14 , wherein the proxy server is a gateway to the LMR network.

19 . The method of claim 14 , wherein, prior to mutual authentication of the MS and the SwMI and after establishment of the secure IP session with the MS, the proxy server restricts access of the MS to the LMR network.

20 . The method of claim 14 , wherein the MS connects to the proxy server from at least one selected from the group consisting of cellular network and a WiFi network, and mutually authenticating the MS with the SwMI is performed after authentication of the MS to the cellular network or the WiFi network.