ASC/X9 - ANSI X9 TR-34
Interoperable Method for Distribution of Symmetric Keys using Asymmetric Techniques: Part 1 – Using Factoring-Based Public Key Cryptography Unilateral Key Transport
|Publication Date:||28 August 2012|
This document describes a method consistent with the requirements of ANS X9.24-2 Retail Financial Services Symmetric Key Management - Part 2: Using Asymmetric Techniques for the Distribution of Symmetric Keys for the secure exchange of keys using asymmetric techniques between two devices that share asymmetric keys. This method is designed to operate within the existing capabilities of devices used in the retail financial services industry.
This is an implementation of the Unilateral Key Transport Method defined in ANS X9.24-2.
This document is not a security standard and is not intended to establish security requirements. It is intended instead to provide an interoperable method of implementing security requirements and policies.
ANS X9.24-2 describes the security requirements for systems that distribute symmetric keys using asymmetric techniques. The security requirements are consistent across all systems; ANS X9.24-2 does not distinguish between types of systems or alter the security requirements depending upon the environment of the entities in the system. While this is the correct approach for security requirements, the implementation requirements on systems will vary depending upon the properties of the system.
This document specifies an interoperable method for one particular situation - the Distribution of Symmetric Keys using Asymmetric Techniques from a Single Key Distribution Host (KDH) to many Key Receiving Devices (KRDs). The KDH is assumed to be operated in a controlled environment (as specified in reference 4); the KRDs may operate in uncontrolled environments.
This interoperable method could also be used to exchange keys between peers, where one is administratively designated as the KDH and one as the KRD.
The KDH and the KRD are assumed to have an administrative understanding of the type and key characteristics of the symmetric key that is exchanged, as for a terminal master key. As such, the key exchanged is treated by this protocol as a binary blob.
This document uses the term KRD to denote the Key Receiving Device; The KRD is a Tamper Resistant Security Module (TRSM) such as a PIN Encrypting Device (PED), a Encrypting PIN PAD (EPP), or a Host Security Module (HSM).
Within the confines of this protocol, the KRD can only respond to commands from a KDH, i.e. the KRD is a slave KRD.