OpenBSD's Security Journey: From IPSec to Immutable Memory

This article details the evolution of software and security concepts developed and maintained by the OpenBSD project, spanning from 1993 to 2024. OpenBSD has consistently been at the forefront of security, and this overview highlights its numerous security features, including IPSec, IPv6, privilege separation, privilege revocation, stack protector, W^X, ASLR, PIE, random-data memory, SROP mitigation, library order randomization, and the cutting-edge immutable memory. These features combine to create OpenBSD's robust security architecture, providing users with a strong security foundation.