Design a tamper-evident video chain-of-custody audit system
Design a Tamper-Evident Video Chain-of-Custody Audit System
Design a scalable, tamper-evident audit logging system specifically for video evidence, ensuring an accurate and legally defensible chain of custody. The system must meticulously record all actions related to an asset (e.g., upload, view, redact/delete sensitive data, transcribe), guarantee no event loss, and fully support legal discovery processes.
Context and Assumptions
- Multi-tenant Environment: The system must support thousands of agencies and millions of assets (videos, photos, transcripts).
- Event Rate: It must handle a peak audit event rate of 10–50k events/sec, with a steady state of 1–5 billion events/month.
- Legal Defensibility: The chain-of-custody must be legally defensible, providing immutable, verifiable proof of event history.
- Offline Handling: Devices and users may be offline and later reconnect; the system must gracefully handle late and out-of-order arrivals without any loss of data.
Specify the Following
- Functional and non-functional requirements.
- Architecture and storage choices (e.g., append-only log, replication, WORM/immutable storage).
- Event schema, ordering, idempotency, and delivery guarantees (exactly-once vs. at-least-once).
- Integrity mechanisms (hash chaining/Merkle trees, digital signatures), encryption and key management, and access controls.
- Scalability, partitioning, and backpressure handling.
- APIs and query patterns for auditors and investigators.
- Retention policies, legal hold, and compliance considerations.
- Monitoring, audit-of-the-auditor, and disaster recovery.
- Cost/latency trade-offs and capacity planning.
- Testing, verification, and rollout plan.
AI interview prep
Core dilemma
Achieving absolute, legally defensible data immutability and tamper-evidence for high-volume, real-time audit logs in a distributed, multi-tenant environment, while maintaining high availability, scalability, and cost-effectiveness, especially with offline client synchronization challenges.
3 tradeoffs and 3 stress tests locked
Interview prep
Unlock the interviewer X-Ray rubric, tradeoff matrix, stress tests, clarifying questions, and key concepts.
Design a tamper-evident video chain-of-custody audit system
Design a Tamper-Evident Video Chain-of-Custody Audit System
Design a scalable, tamper-evident audit logging system specifically for video evidence, ensuring an accurate and legally defensible chain of custody. The system must meticulously record all actions related to an asset (e.g., upload, view, redact/delete sensitive data, transcribe), guarantee no event loss, and fully support legal discovery processes.
Context and Assumptions
- Multi-tenant Environment: The system must support thousands of agencies and millions of assets (videos, photos, transcripts).
- Event Rate: It must handle a peak audit event rate of 10–50k events/sec, with a steady state of 1–5 billion events/month.
- Legal Defensibility: The chain-of-custody must be legally defensible, providing immutable, verifiable proof of event history.
- Offline Handling: Devices and users may be offline and later reconnect; the system must gracefully handle late and out-of-order arrivals without any loss of data.
Specify the Following
- Functional and non-functional requirements.
- Architecture and storage choices (e.g., append-only log, replication, WORM/immutable storage).
- Event schema, ordering, idempotency, and delivery guarantees (exactly-once vs. at-least-once).
- Integrity mechanisms (hash chaining/Merkle trees, digital signatures), encryption and key management, and access controls.
- Scalability, partitioning, and backpressure handling.
- APIs and query patterns for auditors and investigators.
- Retention policies, legal hold, and compliance considerations.
- Monitoring, audit-of-the-auditor, and disaster recovery.
- Cost/latency trade-offs and capacity planning.
- Testing, verification, and rollout plan.