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.