White Paper

WHITE PAPER Buy vs Build: Deploying a Cyber Survivable Operating Environment mrcy.com 4 RelianceOne OE stands out from these approaches by delivering survivability as a product rather than as a program-by-program integration exercise, a buy vs build approach. Competing efforts concentrate either on detection capabilities, which assumes recovery happens after the engagement, or on compliance artifacts, which quantify process adherence rather than outcome. In conjunction, the sustainment platform delivers measurable survivability outcomes and addresses a real gap in cyber assessment and evaluation services. THE RELIANCEONE OE Mercury 's RelianceOne suite is a mature, fielded solution providing layered security for embedded and tactical systems. The suite includes RelianceOne Trusted Platform (formerly RelianceOne Secure Boot), a measured-boot capability and kernel protection hypervisor for commodity Intel x86 processors; RelianceOne for Linux, a hardened operating environment with cryptographically coupled Mandatory Access Controls (MAC), data-at-rest protections, and novel policy enforcement that hinders exploit development and reduces the impact of vulnerable applications and services; and RelianceOne for KVM, a secure virtualization host for tactical workloads. Together, these components deliver protection from boot through runtime, safeguarding mission-critical applications and data against modification, reconfiguration, and reverse engineering. At Technology Readiness Level (TRL) 9, RelianceOne has already been integrated by major defense wprimes into deployed systems. It provides continuous protection across multiple dimensions: secure boot attestation, operating system hardening, runtime enforcement, data-at-rest confidentiality and authenticity, and hypervisor-level isolation. RelianceOne achieves this without requiring significant rework between kernel versions and configurations, because it leverages stable Linux kernel APIs wherever possible. That design choice keeps the solution maintainable and compatible across Linux versions, reducing lifecycle costs and accelerating security validation. Tooling and automation support enables straightforward integration into existing build and release pipelines, making RelianceOne a low-risk insertion for programs seeking to improve survivability without disrupting production schedules. The RelianceOne OE includes mission-aware containment, an architecture that distinguishes between mission-critical and non-critical functions and isolates them accordingly. It also includes an advanced allowlisting feature. Today 's allowlisting solutions only verify binary integrity, the goal being to defeat efforts to execute or install malware. But adversaries who gain access can also turn authorized applications to malicious purposes. Mission-aware containment in the RelianceOne OE includes RelianceOne for Linux policies that facilitate code signing and application allowlisting and also enforce an immutable system configuration by explicitly authenticating application configuration files and command-line parameters. When an adversary compromises a system and attempts to leverage an available and authorized executable, a Python interpreter for example, the adversary cannot use that executable in any manner they choose, such as enumerating processes or probing the file system. Next, by leveraging the compartmentalization capabilities of RelianceOne, the RelianceOne OE confines a compromised application, restricts its privileges, and prevents propagation to mission-essential processes. The goal is not just fault tolerance, but mission persistence under active attack. Finally, RelianceOne OE's policy enforcement goes beyond denying and constraining an adversary who has gained access to a mission system. Policy denials and other access violations are also plumbed to an Event and Response Application Programming Interface (API). The API responds to potential compromises in a manner that alerts the operator, degrades adversary capabilities, prioritizes execution of mission- essential processes, and can intelligently initiate failover of redundant systems. Using the existing Event and Response API allows the specific mapping of events to responses to be tailored to the CONOPS and threat model of a target system, without rework. A CYBER SURVIVABILITY SUSTAINMENT PLATFORM Complementing the RelianceOne OE, the sustainment platform establishes and manages trusted baselines and enables rapid reconstitution and configuration control across a system's operational lifecycle. Under a survivability paradigm, the assumption is that the adversary will successfully maneuver and gain a position from which to impact the tactical operation of a combat system. Holding that as an axiom, it follows that contested engagements will dictate the need to recover to a trusted configuration, to a configuration as free from vulnerabilities as possible. Rapidly and intelligently applying updates to a configuration requires reliable information about vulnerabilities. System and application vulnerabilities are typically communicated using the Common Vulnerabilities and Exposures (CVE) protocol. The protocol uses several metrics to formulate a severity score, and organizations use that score to prioritize the urgency of pushing patches. Today, however, severity decisions, and by extension urgency decisions, are made assuming a standard, unprotected, Linux-based operating environment. The RelianceOne OE is not such a system, and patching decisions that affect the configuration of the operating environment should therefore not rely on upstream CVE scores. As such Mercury 's sustainment platform

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