“德育故事”和“德育案例”征稿启 ...ppt

Applications of Logic in Computer Security Jonathan Millen SRI International Areas of Application Multilevel Operating System Security “Orange Book,” Commercial Trusted Product Evaluation, A1-level Emphasis on secrecy, security/clearance levels Access Control Policies Discretionary or role-based policies Emphasis on application-specific policies, integrity Public-Key Infrastructure and Trust Management Network and distributed system security Digitally signed certificates for identity and privileges Cryptographic Authentication Protocols For network communication confidentiality and authentication Other areas: databases, firewalls/routers, intrusion detection Contributions of Logic Undecidability Results Safety problem for discretionary access control Cryptographic protocol analysis Theorem Proving Environments Verifying correctness of formal OS specifications Inductive proofs of cryptographic protocols Logic Programming Prolog programs for cryptographic protocol analysis, trust management Model Checking For cryptographic protocol analysis Specialized Logics For cryptographic protocol analysis, trust management Multilevel Operating System Security Motivated by protection of classified information in shared systems High-assurance (A1) systems may protect Secret data from uncleared users Architecture: trusted OS kernel, hardware support Abstract system model of access control: Bell-LaPadula (ca. 1975) Structured state-transition system: subject-object access matrix, levels Security invariants and transition rules (for OS functions) “Formal Top-Level Specification” (FTLS) More detailed state-transition system Formal Proofs: Model transitions satisfy invariants FTLS is an interpretation of the system model Carried out in environments like Gypsy, FDM, HDM Some FTLS errors reflected in code were discovered Of Historical Interest Access Control Policies Safety Problem Subject-object-rights matrix “rights” were arbitrary, representing different kinds of access Operations