Banking on interoperability: Secure, interoperable credential management

An interoperable credential system allows users to reference a single asymmetric key pair to logon tomultiple web sites and digitally sign transactions. Models that govern how keys are created, authorized, validated, and revoked are a crucial part of such a system. Thesemodels have security, scalability, and liability implications for businesses, so the requirements vary depending on the parties involved. However, the prevailing the public key infrastructure (PKI) system does not meet these diverse needs. PKI requires a certificate authority (CA) to act as a trusted third party for the parties in a transaction. For example, PKI features a receiver key validationmodel that requires the receiver of the transaction to communicate with a CA to validate the sender’s key used to sign a transaction. These aspects conflict with liability concerns and interoperability goals of businesses doing high-value transactions such as wholesale banking. This paper presents Partner Key Management (PKM) as a mechanism which sufficiently addresses security and liability concerns of businesses performing highvalue online transactions, and uses wholesale banking as themotivating example. PKM does not rely on a trusted thirdparty, and features several flexible revocationmodels to accommodate diverse regulations. PKM is not merely a proposal. Rather, the financial industry has implemented the technology in someof itswholesalebanking sites thereby securingmillions of dollars of transactions every day. Finally, this paper justifies the security of PKM and its flexible revocationmodels; and illustrates the justificationwith proofs through formal logic. 2014 Elsevier B.V. All rights reserved.