| name | implementing-log-integrity-with-blockchain |
| description | Builds an append-only log integrity chain using SHA-256 hash chaining, where each entry incorporates the previous entry's hash so tampering invalidates all subsequent hashes; covers log ingestion (syslog/JSON/plain text), chain verification, pinpoint tamper detection, and checkpoint anchoring to external timestamping services. Use for tamper-evident log storage for compliance or forensics, or to verify whether log entries were altered. |
| domain | cybersecurity |
| subdomain | security-operations |
| tags | ["log-integrity","tamper-detection","hash-chaining","sha-256","audit-logging","security-operations"] |
| version | 1.0 |
| author | mahipal |
| license | Apache-2.0 |
| nist_csf | ["DE.CM-01","RS.MA-01","GV.OV-01","DE.AE-02"] |
| mitre_attack | ["T1078","T1190","T1059"] |
Implementing Log Integrity with Blockchain
When to Use
- When deploying or configuring implementing log integrity with blockchain capabilities in your environment
- When establishing security controls aligned to compliance requirements
- When building or improving security architecture for this domain
- When conducting security assessments that require this implementation
Prerequisites
- Familiarity with security operations concepts and tools
- Access to a test or lab environment for safe execution
- Python 3.8+ with required dependencies installed
- Appropriate authorization for any testing activities
Instructions
- Install dependencies:
pip install requests
- Ingest log entries from syslog, JSON, or plain text files.
- For each entry, compute SHA-256 hash of: previous_hash + timestamp + log_content.
- Store the chain as a JSON ledger with entry index, timestamp, content hash, previous hash, and chain hash.
- Verify chain integrity by recomputing all hashes and detecting breaks.
- Optionally anchor checkpoint hashes to an external timestamping service.
python scripts/agent.py --log-file /var/log/syslog --chain-file log_chain.json --verify --output integrity_report.json
Examples
Chain Entry Structure
{"index": 42, "timestamp": "2024-01-15T10:30:00Z", "content_hash": "a1b2c3...",
"prev_hash": "d4e5f6...", "chain_hash": "SHA256(prev_hash + timestamp + content_hash)"}
Tamper Detection
If entry 42 is modified, chain_hash[42] will not match SHA256(chain_hash[41] + ...), and all entries from 42 onward will be flagged as invalid.
