Integrity

Cybersecurity 19 Sep 2026 6 min read

IMA Appraisal Binds File Access to Integrity Metadata

A file can have ordinary read or execute permission and still fail an integrity check at the kernel boundary. Linux Integrity Measurement Architecture (IMA) appraisal can apply policy rules at selected hooks and require file content to agree with integrity metadata before the covered operation proceeds. This adds a content-integrity condition to access decisions without turning Unix mode bits or application authorization into integrity mechanisms. IMA contains related but distinct functions. Measurement records file state in an integrity measurement list and can extend measurements into a TPM. Appraisal evaluates a file against integrity metadata and can reject access when policy and enforcement mode require a valid result. Audit records security-relevant state. A deployment that only measures files gains evidence about observed state; it does not automatically gain the blocking behavior associated with appraisal.

Cybersecurity Linux

Cybersecurity 17 Sep 2026 7 min read

fs-verity Makes File Data Integrity a Read-Time Property

A host may need to keep independently updated executables, packages, models, or data on a writable filesystem while still detecting modification of file contents after an artifact has been accepted. A one-time userspace hash can identify the bytes at one moment, but it does not make later reads depend on that measurement. The file may be opened again, pages may be evicted and reloaded, and storage below the page cache may return different data.

Cybersecurity Linux Security

Cybersecurity 05 Sep 2026 11 min read

Verify Artifacts Before Running Them

Downloading software is often treated as the end of a trust decision: the file came from the expected page, so the next step is to run it. That shortcut is risky. A release archive, installer, container image, or build tool can be corrupted in transit or storage, replaced at a distribution point, or fetched from an unexpected source while keeping a plausible filename. Running the wrong bytes can turn a distribution failure into code execution inside a developer workstation, build system, or production environment. The defensive goal is therefore not merely to obtain an artifact. It is to establish that the bytes you received are the bytes an accepted publisher intended you to use.

Cybersecurity Software Supply Chain

Cybersecurity 04 Sep 2026 8 min read

Verify Dependency Integrity Before Installation

A dependency declaration such as library = 2.4.1 tells a package manager which release you intend to use. It does not, by itself, prove that the bytes being installed are the same bytes you previously reviewed, tested, or approved. That distinction matters when dependencies cross a trust boundary. Packages may come through registries, mirrors, caches, proxies, build systems, or internal artifact stores. If unexpected bytes are accepted somewhere along that path, a familiar package name and version can create false confidence.

Cybersecurity Software Supply Chain