Hardware-Based Zero-Knowledge Strong Authentication (H0KSA)

Abstract

Systems and methods are provided for a device to engage in a zero-knowledge proof with an entity requiring authentication either of secret material or of the device itself. The device may provide protection of the secret material or its private key for device authentication using a hardware security module (HSM) of the device, which may include, for example, a read-only memory (ROM) accessible or programmable only by the device manufacturer. In the case of authenticating the device itself a zero-knowledge proof of knowledge may be used. The zero-knowledge proof or zero-knowledge proof of knowledge may be conducted via a communication channel on which an end-to-end (e.g., the device at one end and entity requiring authentication at the other end) unbroken chain of trust is established, unbroken chain of trust referring to a communication channel for which endpoints of each link in the communication channel mutually authenticate each other prior to conducting the zero-knowledge proof of knowledge and for which each link of the communication channel is protected by at least one of hardware protection and encryption.

1 . A system comprising:
 a device configured to engage in a zero-knowledge proof with an entity via a protected communication channel to authenticate a secret material; and   a hardware security module (HSM) within the device, wherein:
 the HSM protects the secret material so that the secret material is inaccessible by unauthenticated and unintended entities, and 
 the HSM communicates via the protected communication channel with the entity; and 
   the communication channel provides an unbroken chain of trust between the device and the entity.   
     
     
         2 . The system of  claim 1 , wherein:
 the secret material is a private key material;   the private key material is unique and resistant to forgery and to being guessed so that the private key material serves as an identity of the device; and   the private key material is a proof material for a zero-knowledge proof of knowledge to authenticate the device.   
     
     
         3 . The system of  claim 1 , wherein:
 the secret material is a private key material;   the private key material is unique so that the private key material serves as an identity of the device;   the private key material is a proof material for a zero-knowledge proof of knowledge to authenticate the device; and   the private key material remains private after the zero-knowledge proof of knowledge authentication of the device is completed so that the private key material is not disclosed to the entity.   
     
     
         4 . The system of  claim 1 , wherein:
 the HSM includes a secure vault;   the secret material is stored in the secure vault; and   the secure vault provides hardware-based protection of the secret material.   
     
     
         5 . The system of  claim 1 , wherein the HSM comprises at least one of a Trusted Platform Module (TPM), a Mobile Trusted Module (MTM), a secure element (SE), an embedded secure element (eSE), a secure memory card, a Secure Domain (SD) card, or a Trusted Flash memory. 
     
     
         6 . The system of  claim 1 , wherein the communication channel is protected by encryption. 
     
     
         7 . The system of  claim 1 , wherein the communication channel is hardware protected. 
     
     
         8 . The system of  claim 1 , wherein:
 the communication channel includes one or more communication hops, each hop having two endpoints, wherein
 each hop of the communication channel is protected; and 
 the endpoints of each hop mutually authenticate each other so that the communication channel provides an end-to-end chain of trust from the device to the entity. 
   
     
     
         9 . The system of  claim 1 , wherein a biometric device is used to initiate the authentication process. 
     
     
         10 . A method comprising:
 protecting a secret material in a hardware security module of a device;   establishing an end-to-end chain of trust over a communication channel, wherein:
 the channel has two endpoints, the hardware security module being at one of a first endpoint and a second endpoint; and 
 an unbroken chain of trust is established between the first endpoint and the second endpoint of the channel; and 
   authenticating the secret material wherein the first endpoint and second endpoint engage in a zero-knowledge proof via the communication channel to authenticate the secret material.   
     
     
         11 . The method of  claim 10 , further comprising:
 authenticating the device using a private key as proof material in a zero-knowledge proof of knowledge wherein the private key remains private after authentication of the device, and wherein:
 protecting the secret material comprises protecting the private key, wherein the private key serves to uniquely identify the device; and 
 authenticating the secret material comprises using the private key as proof material in the zero-knowledge proof of knowledge to authenticate the device. 
   
     
     
         12 . The method of  claim 10 , wherein protecting the secret material comprises providing hardware protection including storing the secret material in a secure vault comprising a read-only memory (ROM). 
     
     
         13 . The method of  claim 10 , wherein protecting the secret material comprises using a trusted agent to store the secret material in a secure vault. 
     
     
         14 . The method of  claim 10 , wherein protecting the secret material comprises storing the secret material in at least one of a Trusted Platform Module (TPM), a Mobile Trusted Module (MTM), a secure element (SE), an embedded secure element (eSE), a secure memory card, a Secure Domain (SD) card, or a Trusted Flash memory. 
     
     
         15 . The method of  claim 10 , wherein establishing the end-to-end chain of trust comprises protecting the communication channel by encryption. 
     
     
         16 . The method of  claim 10 , wherein establishing the end-to-end chain of trust comprises providing hardware protection for the communication channel. 
     
     
         17 . The method of  claim 10 , wherein:
 the communication channel includes one or more communication hops, each hop having two endpoints; and   establishing the end-to-end chain of trust comprises:
 protecting each hop of the communication channel; and 
 mutually authenticating each other by the endpoints of each hop. 
   
     
     
         18 . A method comprising:
 protecting a private key in a secure vault of a device; and   using a zero-knowledge proof of knowledge with the private key as proof material to authenticate the device via an unbroken, end-to-end chain of trust so that the private key remains private to the device.   
     
     
         19 . The method of  claim 18 , wherein protecting the private key comprises storing the private key in a read-only memory (ROM) using a trusted agent. 
     
     
         20 . The method of  claim 18 , further comprising:
 conducting the zero-knowledge proof of knowledge via a communication channel, wherein:   endpoints of the communication channel mutually authenticate each other prior to conducting the zero-knowledge proof of knowledge; and   each link of the communication channel is protected by at least one of hardware protection and encryption.