Benchmarking the Security Protocol and Data Model (SPDM) for component authentication

TL;DR

This paper evaluates the performance impact of the Security Protocol and Data Model (SPDM) at the firmware level by implementing it on virtual devices and measuring its overhead on data transfer operations.

Contribution

It provides the first performance benchmarking of SPDM in real-world scenarios, analyzing its overhead on virtual device communication and storage performance.

Findings

SPDM bootstrap time is around tens of milliseconds.

Performance impact varies with workload pattern.

Sequential read/write operations are significantly slowed down.

Abstract

Efforts to secure computing systems via software traditionally focus on the operating system and application levels. In contrast, the Security Protocol and Data Model (SPDM) tackles firmware level security challenges, which are much harder (if at all possible) to detect with regular protection software. SPDM includes key features like enabling peripheral authentication, authenticated hardware measurements retrieval, and secure session establishment. Since SPDM is a relatively recent proposal, there is a lack of studies evaluating its performance impact on real-world applications. In this article, we address this gap by: (1) implementing the protocol on a simple virtual device, and then investigating the overhead introduced by each SDPM message; and (2) creating an SPDM-capable virtual hard drive based on VirtIO, and comparing the resulting read/write performance with a regular, unsecured implementation. Our results suggest that SPDM bootstrap time takes the order of tens of milliseconds, while the toll of introducing SPDM on hard drive communication highly depends on specific workload patterns. For example, for mixed random read/write operations, the slowdown is negligible in comparison to the baseline unsecured setup. Conversely, for sequential read or write operations, the data encryption process becomes the bottleneck, reducing the performance indicators by several orders of magnitude.