| name | implementing-log-integrity-with-blockchain |
| description | Build an append-only log integrity chain using SHA-256 hash chaining for tamper detection. Each log entry is hashed with the previous entry's hash to create a blockchain-like structure where modifying any entry invalidates all subsequent hashes. Implements log ingestion, chain verification, tamper detection with pinpoint identification, and periodic checkpoint anchoring to external timestamping services. |
| domain | cybersecurity |
| subdomain | security-operations |
| tags | ["implementing","log","integrity","with"] |
| version | 1.0 |
| author | mahipal |
| license | Apache-2.0 |
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.
