Kaiza MCP Server

--- title: "ADR-003: Cryptographic Audit Logging" description: "Decision to implement immutable, cryptographic audit logging for all system operations" version: "2.0.0" last_updated: "2026-01-31" review_date: "2026-04-30" owners: ["architecture-team"] tags: ["adr", "audit", "security", "cryptography", "compliance"] audience: ["technical", "executive"] --- # ADR-003: Cryptographic Audit Logging ## Status Accepted ## Context Enterprise environments require comprehensive audit trails for: - Regulatory compliance (SOX, GDPR, HIPAA, etc.) - Security incident investigation and forensics - Operational accountability and responsibility tracking - Quality assurance and process improvement Traditional audit logging approaches have limitations: - **Mutable Logs**: Log files can be modified or deleted - **Limited Integrity**: No cryptographic verification of log entries - **Incomplete Coverage**: Gaps in logging critical operations - **Poor Performance**: Logging can impact system performance - **Complex Analysis**: Difficult to analyze and correlate events The need exists for an audit system that provides: - **Immutability**: Logs cannot be tampered with after creation - **Cryptographic Integrity**: Each entry is cryptographically verified - **Comprehensive Coverage**: All relevant operations are logged - **High Performance**: Minimal impact on system operations - **Easy Analysis**: Structured format for efficient analysis ## Decision Implement an immutable, cryptographic audit logging system with the following characteristics: ### Log Structure Each audit log entry contains: - **Timestamp**: Precise timestamp of the operation - **Session ID**: Unique identifier for the session - **Operation Type**: Type of operation performed - **Actor**: Role and identity of the performer - **Target**: Resource or object being operated on - **Metadata**: Additional context and parameters - **Hash**: Cryptographic hash of the log entry - **Previous Hash**: Hash of the previous entry (blockchain-like) ### Immutable Storage - **Append-Only Format**: Logs stored in append-only JSONL format - **Chain Verification**: Each entry references the previous entry's hash - **Cryptographic Signing**: Entries are cryptographically signed - **Tamper Detection**: Any modification breaks the hash chain ### Comprehensive Coverage - **Session Management**: All session initialization and termination - **Plan Operations**: Plan creation, approval, and execution - **File Operations**: All file read and write operations - **Role Changes**: Role switching and permission changes - **Security Events**: Authentication, authorization, and access violations ## Rationale ### Security Benefits - **Tamper Evidence**: Any log modification is immediately detectable - **Chain of Custody**: Complete, verifiable chain of events - **Forensic Value**: High-quality evidence for security investigations - **Deterrence**: Knowledge of comprehensive logging deters malicious activity ### Compliance Benefits - **Regulatory Requirements**: Meets stringent regulatory audit requirements - **Standards Compliance**: Aligns with industry security standards - **Audit Readiness**: Always prepared for audits and inspections - **Documentation**: Automatic documentation of all system activities ### Operational Benefits - **Accountability**: Clear responsibility assignment for all actions - **Troubleshooting**: Detailed information for problem diagnosis - **Performance Analysis**: Data for system performance optimization - **Process Improvement**: Insights for workflow optimization ## Alternatives Considered ### Database-Based Logging **Pros**: Structured queries, transaction support, easy backup **Cons**: Single point of failure, potential for data corruption, complex infrastructure ### File-Based Logging (Plain Text) **Pros**: Simple implementation, easy to read, minimal dependencies **Cons**: No integrity protection, easy to modify, limited structure ### Third-Party Logging Services **Pros**: Managed service, advanced features, scalability **Cons**: External dependencies, cost, data privacy concerns ### Blockchain-Based Logging **Pros**: Maximum immutability, distributed consensus, transparency **Cons**: High complexity, performance overhead, integration challenges ## Consequences ### Positive Consequences - **Enhanced Security**: Tamper-evident logging improves security posture - **Compliance Assurance**: Meets stringent regulatory requirements - **Operational Insight**: Comprehensive data for analysis and optimization - **Trust Building**: Demonstrates commitment to transparency and accountability ### Negative Consequences - **Storage Requirements**: Significant storage requirements for log data - **Performance Impact**: Potential performance impact from cryptographic operations - **Complexity**: Increased system complexity and maintenance requirements - **Cost**: Additional costs for storage, backup, and analysis tools ### Neutral Consequences - **Integration Requirements**: Need for integration with log analysis tools - **Training Requirements**: Staff training for log analysis and management - **Process Changes**: Modifications to existing operational procedures ## Implementation Notes ### Technical Implementation - **File Format**: JSONL (JSON Lines) format for efficient parsing - **Hash Algorithm**: SHA-256 for cryptographic hashing - **Chain Structure**: Each entry contains previous entry hash - **Rotation**: Log rotation with archive preservation ### Security Considerations - **Access Controls**: Strict access controls for log files - **Backup Strategy**: Secure backup with integrity verification - **Retention Policy**: Defined retention periods for compliance - **Privacy Protection**: Sensitive data protection and anonymization ### Performance Considerations - **Asynchronous Logging**: Non-blocking log writes - **Buffer Management**: Efficient buffering for high-volume operations - **Compression**: Log compression for storage optimization - **Indexing**: Efficient indexing for log analysis ### Integration Points - **SIEM Integration**: Integration with security information and event management - **Compliance Tools**: Integration with compliance reporting tools - **Monitoring Systems**: Integration with system monitoring and alerting - **Analytics Platforms**: Integration with log analytics and business intelligence ## Related Decisions - [ADR-001: Dual-Role Governance Model](./001-dual-role-governance.md) - [ADR-002: Plan-Based Authorization System](./002-plan-based-authorization.md) - [ADR-004: Zero-Trust Execution Model](./004-zero-trust-execution.md) --- **Decision Date**: 2026-01-19 **Decision Maker**: ATLAS-GATE MCP Architecture Team **Review Date**: 2026-04-19 **Status**: Accepted and Implemented