System and method for pre-shared key (PSK) based content signing for tamper resistance
The method provides an automated and scalable system for the generation, distribution, management of symmetric pre-shared keys (PSKs) to applications executing on headless and mobile devices. It helps achieve device protection, application security, and data protection with data authenticity and confidentiality in intra-device, inter-device, device-to-edge, and device-to-cloud communications. It helps Transport Layer Security (TLS) enabled applications dynamically acquire and renew PSKs and use identity hints for PSK based authentication ceremony during a TLS handshake. It helps client-server applications dynamically acquire and renew PSKs using keyed-hash message authentication code (HMAC) for data integrity and authenticity, content signing, and data encryption for confidentiality. It helps manage and distribute API shared secrets and API access tokens required for authenticated API requests and API security. It helps applications (producers, brokers, and consumers of content) with PSKs for supply chain tamper resistance. It helps real-time low-latency applications with selective encryption of partial messages.
1. A method of generating, distributing, and managing a lifecycle of a symmetric pre-shared key (PSK) used in certificate-less keyed hash message authentication code (HMAC) based content signing for tamper resistance, for use between applications executing on distributed devices including a producer application executing on a producer device, a consumer application executing respectively on a consumer device, a key distribution service (KDS), a KDS proxy, a KDS interface, a symmetric KDS member M-PSK, a M-PSK identity hint, a tenant identifier, a device group identifier associated with the tenant identifier, a member domain associated with the group identifier, an application identifier associated with the group identifier, a key record, a dynamic host configuration protocol (DHCP) server, and a domain name system (DNS) server, the method comprising:
authenticating, with the KDS, by the producer application executing on the producer device, using the tenant identifier, the symmetric KDS member PSK (M-PSK) and the M-PSK identity hint, wherein the producer device is registered by a DNS hostname on the DNS server configured with the KDS or the KDS proxy, and is configured as a first member of a device group on the KDS; and
creating, by a producer application on the KDS, a symmetric pre-shared key with an associated pre-shared key (PSK) identity hint; and
signing, by the producer application executing on the producer device, digital content using the created pre-shared key; and
generating, by the producer application executing on the producer device, an associated signature manifest with the tenant identifier, the group identifier, the digital signature, and the pre-shared key identity hint; and
sending, by the producer application executing on the producer device to the consumer application executing on the consumer device, the signed digital content and the associated signature manifest; and
authenticating, with the KDS, by the consumer application executing on the consumer device, using the tenant identifier, the symmetric KDS member PSK (M-PSK) and the M-PSK identity hint, wherein the consumer device is registered by a DNS hostname on the DNS server, configured with the KDS or the KDS proxy, and is configured as a second member of the device group on the KDS; and
receiving, by the consumer application, the signed digital content and the associated signature manifest with the tenant identifier, the group identifier, the digital signature, and the pre-shared key identity hint; and
retrieving, by the consumer application from the KDS, using at least the tenant identifier, the group identifier, and the pre-shared key identity hint, the pre-shared key for the pre-shared key identity hint in the received signature manifest; and
verifying, by the consumer application, the received signed digital content using the retrieved pre-shared key to regenerate the digital signature and to compare for a match with the digital signature in the received signature manifest.
2. The method of claim 1 , wherein a device member authentication handshake is performed by the KDS interface on the producer and consumer devices using the tenant identifier, the device member PSK (M-PSK) and the M-PSK identity hint as a first factor of device authentication, and further wherein the session key is generated using a key exchange handshake between the KDS interface and the KDS or the KDS proxy, and further wherein a device member validation is performed as a second factor of device authentication by:
performing, by the KDS or the KDS proxy, a DNS reverse lookup of a device member IP address to query for the DNS hostname; and
retrieving, by the KDS or the KDS proxy, the DNS hostname from a resource record in a DNS response; and
comparing and matching, by the KDS or the KDS proxy, the retrieved DNS hostname with the device member identifier in the KDS requests.
3. The method of claim 2 , wherein a device authentication and a plurality of key exchange handshakes are performed over a connection-less UDP or connection-oriented TCP transport protocol, without requiring a security transport protocol.
4. The method of claim 1 , wherein the KDS interface provides a plurality of application programming interfaces (APIs), wherein the producer and consumer applications send a plurality of requests for key operations directly to the KDS and receive a plurality of responses for key operations directly from the KDS, or wherein the producer and consumer applications send a plurality of requests for key operations indirectly through the KDS proxy and receive a plurality of responses for key operations indirectly through the KDS proxy.
5. The method of claim 1 , wherein the producer and consumer devices are registered by a unique DNS hostname in the domain on a local DNS server with an IP address (A) record and a PTR record used in a DNS hostname reverse lookup.
6. The method of claim 1 , wherein on the KDS, the producer and consumer devices are configured as members of a tenancy associated with the tenant identifier and the device group associated with the tenant identifier, and further wherein the device group is configured with key records that include key instances used in generating and verifying digital signatures.
7. The method of claim 1 , wherein a key record configured for the device group on the KDS includes a key expiration timestamp and a key status to manage automatic key renewal, key rotation, and key revocation operations on the KDS.
8. The method of claim 1 , wherein prior to acquiring the pre-shared key from the KDS by the producer application, the pre-shared key is created on the KDS by the producer application with the producer member device as a key creator and with restricted key usage permissions for data authentication, data encryption, content signing, broadcast signing, broadcast encryption, multicast signing, multicast encryption, token signing, or token encryption operations.
9. The method of claim 1 , wherein the acquiring of the pre-shared keys from the KDS by the consumer application restricts key usage based on permissions configured by a key creator.
10. A method of claim 1 , wherein an authenticated member device's request for any key operation, based on the group identifier and the pre-shared key identity hint, is processed by the KDS and permitted based on a match of a member domain with a domain derived from a plurality of resource records retrieved by a DNS reverse lookup for a member device DNS hostname.
11. A method of claim 1 , wherein an authenticated member device's request for any key operation, based on the group identifier, the pre-shared key identity hint, and the application identifier, is processed by the KDS and permitted based on a match with an application identifier associated with the group identifier, wherein the KDS is configured to allow or deny the key operation.
12. A method of claim 1 , wherein device specific information configured as extended custom attributes for a member device is retrieved from the DHCP server using a plurality of extended KDS interface APIs to automate local device configuration and export vendor specific member device information to the KDS.
13. A method of claim 1 , wherein an authenticated member device's request for any key operation, based on the group identifier and the pre-shared key identity hint, is processed by the KDS and permitted based on a match of the member device tenant identifier with an associated license owner identifier retrieved from the DHCP server as a vendor specific member device information.
14. A method of generating, distributing, and managing a lifecycle of a symmetric pre-shared key (PSK) used in certificate-less keyed hash message authentication code (HMAC) based content signing for tamper resistance, for use between applications executing on distributed devices including a producer application executing on a producer device, a consumer application executing respectively on a consumer mobile device, a key distribution service (KDS), a KDS proxy, a KDS interface, a symmetric KDS member M-PSK, a M-PSK identity hint, a tenant identifier, a device group identifier associated with the tenant identifier, a member domain associated with the group identifier, an application identifier associated with the group identifier, a key record, and a domain name system (DNS) server, a device directory service (DDS), and a mobile service provider (MSP) server, the method comprising:
authenticating, with the KDS, by the producer application executing on the producer device, using the tenant identifier, the symmetric KDS member PSK (M-PSK) and the M-PSK identity hint, wherein the producer device is registered by a DNS hostname on the DNS server configured with the KDS or the KDS proxy, and is configured as a first member of a device group on the KDS;
creating, by a producer application on the KDS, a symmetric pre-shared key with an associated pre-shared key (PSK) identity hint;
signing, by the producer application executing on the producer device, digital content using the created pre-shared key;
generating, by the producer application executing on the producer device, an associated signature manifest with the tenant identifier, the group identifier, the digital signature, and the pre-shared key identity hint;
sending, by the producer application executing on the producer device to the consumer application executing on the consumer mobile device, the signed digital content and the associated signature manifest;
authenticating, with the KDS, by the consumer application executing on the consumer mobile device, using the tenant identifier, the symmetric KDS member PSK (M-PSK) and the M-PSK identity hint, wherein the consumer mobile device is registered by an international mobile subscriber identity (IMSI) on the MSP server, configured with the KDS or the KDS proxy, and is configured as a second member of the device group on the KDS;
receiving, by the consumer application, the signed digital content and the associated signature manifest with the tenant identifier, the group identifier, the digital signature, and the pre-shared key identity hint;
retrieving, by the consumer application from the KDS, using at least the tenant identifier, the group identifier and the pre-shared key identity hint, the pre-shared key for the pre-shared key identity hint in the received signature manifest; and
verifying, by the consumer application, the received signed digital content using the retrieved pre-shared key to regenerate the digital signature and to compare for a match with the digital signature in the received signature manifest.
15. The method of claim 14 , wherein a device member authentication handshake is performed by the KDS interface on the producer device using the tenant identifier, the device member PSK (M-PSK) and the M-PSK identity hint as a first factor of device authentication, and further wherein the session key is generated using a key exchange handshake between the KDS interface and the KDS or the KDS proxy, and further wherein a device member validation is performed as a second factor of device authentication by:
performing, by the KDS or the KDS proxy, a DNS reverse lookup of a device member IP address to query for the DNS hostname; and
retrieving, by the KDS or the KDS proxy, the DNS hostname from a resource record in a DNS response; and
comparing and matching, by the KDS or the KDS proxy, the retrieved DNS hostname with the device member identifier in the KDS requests.
16. The method of claim 14 , wherein a device authentication and a plurality of key exchange handshakes are performed over a connection-less UDP or connection-oriented TCP transport protocol, without requiring a security transport protocol.
17. The method of claim 14 , wherein a device member authentication handshake is performed by the KDS interface on the consumer mobile devices using the device member PSK (M-PSK) and the M-PSK identity hint, and further wherein the session key is generated using a key exchange handshake between the KDS interface and the KDS or the KDS proxy, and further wherein the device member validation is performed by:
receiving, by the KDS from the consumer mobile device, an integrated circuit card identifier (ICCID), an international mobile equipment identity (IMEI), and an IMSI information of the consumer mobile device; and
sending, by the KDS to the consumer mobile device, a nonce for signing by a SIM on the consumer mobile device using an authentication key stored securely with the SIM, wherein a storage location is in a card circuitry or on an applet on the SIM; and
receiving, by the KDS from the consumer mobile device, the signed nonce; and
sending, by the KDS to the mobile services provider of the consumer mobile device, the nonce and the IMSI for signing using an associated authentication key of the consumer mobile device; and
authenticating, by the KDS, the consumer mobile device by comparing and matching the signed nonces received from the consumer mobile device and the mobile service provider to authenticate and validate the consumer mobile device.
18. The method of claim 14 , wherein the KDS interface provides a plurality of application programming interfaces (APIs), wherein the producer and consumer applications send a plurality of requests for key operations directly to the KDS and receive a plurality of responses for key operations directly from the KDS, or wherein the producer and consumer applications send a plurality of requests for key operations indirectly through the KDS proxy and receive a plurality of responses for key operations indirectly through the KDS proxy.
19. The method of claim 14 , wherein on the KDS, the producer and consumer devices are configured as members of a tenancy associated with the tenant identifier and the device group associated with the tenant identifier, and further wherein the device group is configured with key records that include key instances used in generating and verifying digital signatures.
20. The method of claim 14 , wherein a key record configured for the device group on the KDS includes a key expiration timestamp and a key status to manage automatic key renewal, key rotation, and key revocation operations on the KDS.
21. The method of claim 14 , wherein prior to acquiring the pre-shared keys from the KDS by the consumer application, the pre-shared keys are created on the KDS by the producer application with the producer member device as a key creator and with restricted key usage permissions for data authentication, data encryption, content signing, broadcast signing, broadcast encryption, multicast signing, multicast encryption, token signing, or token encryption operations.
22. The method of claim 14 , wherein the acquiring of the pre-shared keys from the KDS by the consumer application restricts key usage based on permissions configured by a key creator.
23. A method of claim 14 , wherein an authenticated member device's request for any key operation, based on the group identifier and the pre-shared key identity hint, is processed by the KDS and permitted based on a match of a member domain with a domain derived from a plurality of resource records retrieved by a DNS reverse lookup for a member device DNS hostname.
24. A method of claim 14 , wherein an authenticated member device's request for any key operation, based on the group identifier, the pre-shared key identity hint, and the application identifier, is processed by the KDS and permitted based on a match with an application identifier associated with the group identifier, wherein the KDS is configured to allow or deny the key operation.
25. A method of claim 14 , wherein an authenticated member device's request for any key operation, based on the group identifier and the pre-shared key identity hint, is processed by the KDS and permitted based on a match of the member device tenant identifier with an associated license owner identifier retrieved from the DDS as a vendor specific member device information.