The Trusted Platform Module (TPM) performs the RSA algorithm on the chip. However, it is much more capable than just an encryption chip. The TPM specification is developed and maintained by the Trusted Computing Group (TCG), an international industry standards body.

TPMs are included on several major vendor laptops including Dell, HP, and even Google Chromebooks. On laptops, TPMs are normally found in the Low Pin Count (LPC) package and are enabled via the BIOS. Embedded devices typically don't support the LPC bus; the TPM on the CryptoCape communicates over the I2C bus.

The software interface to the TPM is via the Trusted Computing Group Software Stack (TSS). In Linux, the TSS is provided by the TrouSerS package. In the next chapter, we'll be using the TPM and also take a closer look at the TPM on the CryptoCape.