Teaching an Old TPM New Tricks: Repurposing for Identity-Based Signatures

A trusted platform module (TPM) is an industry-standard module bound to a system; it provides secure, cryptoprocessor functions such as asymmetric key generation and storage, asymmetric encryption/decryption, cryptographic hashing operations, and much more. Although it may seem useful, this module, ubiquitous in many OEM systems, is often underutilized or not utilized at all. This article presents a way to use the TPM as a secure key-generating authority in a Shamir identity-based signature scheme implementation. The authors demonstrate that the TPM can be used for more than what it's usually documented for. If more such uses can be found, perhaps the TPM will no longer be underutilized.