Tag
access-control
- Jul 6, 2026 Nine Permission Bits, Three Classes, and No Way to Deny How the mode word is checked at open time, why umask subtracts rather than assigns, and what setuid, setgid and the sticky bit change about the check. computing history
- May 5, 2026 POSIX Mode Bits, umask, and the ACL Mask Interaction How the nine permission bits, the setuid and sticky bits, umask filtering, and POSIX ACL entries combine into one effective permission, and why chmod rewrites an ACL mask. security
- Apr 23, 2026 What a Private Field Actually Hides How access control is checked, why private members remain reachable through reflection or linking tricks, and why the module rather than the class is the enforceable boundary. programming languages
- Jan 24, 2026 Relationship Graphs and How ReBAC Checks Resolve Access How relationship tuples model authorization as graph traversal, why depth-bounded checks are the practical answer, and where cycles and fan-out break naive evaluation. security
- Jan 8, 2026 Role Hierarchies and the Reachability Problem in RBAC How role-based access control assigns permissions through roles, why the role hierarchy is a partial order, and why reachability queries and separation-of-duty constraints dominate evaluation cost. security
- Dec 29, 2025 Enforcing Sandbox Policy at BPF LSM Hooks How an eBPF program attached to a kernel LSM hook can decide a security question with access to kernel objects, and why the hook it chooses determines what it can express. virtualization
- Sep 2, 2025 Metadata Filtering Inside Vector Search Why post-filtering a top-k list cannot satisfy a restrictive predicate, how pre-filtering collapses an index walk, and what the middle strategies actually cost. inference systems
- Jan 17, 2025 Authorization Models for Multi-Tenant Data Isolation How tenant identity must be bound into every query and token, why row-level filtering fails when it is optional, and what isolation guarantees separate deployments actually provide. security
- Nov 22, 2024 Reference Monitors and Complete Mediation in Access Control Why an access check only means something if every access passes through it, how the policy decision point is separated from the enforcement point, and where check-then-use gaps appear. security
- Sep 26, 2023 Administrative Models, Safety Analysis, and Sandhu's Schematic Protection Model How to reason about whether a protection system can leak a right, why safety is undecidable in general, and which restricted models admit tractable analysis. security