Architecture for Protecting Critical Secrets in Microprocessors

Abstract

We propose “secret-protected (SP)” architecture to enable secure and convenient protection of critical secrets for a given user in an on-line environment. Keys are examples of critical secrets, and key protection and management is a fundamental problem - often assumed but not solved - underlying the use of cryptographic protection of sensitive files, messages, data and programs. SP-processors contain a minimalist set of architectural features that can be built into a general-purpose microprocessor to provide protection of critical secrets and their computations, without expensive or inconvenient auxiliary hardware. SP-architecture also requires a trusted software module, a few modifications to the operating system, a secure I/O path to the user, and a secure installation process. Unique aspects of our architecture include: decoupling of user secrets from the devices, enabling users to securely access their keys from different networked computing devices; the use of symmetric master keys rather than more costly public-private key pairs; and the avoidance of any permanent or factory-installed device secrets.