HSM-Signer Service (PDF/XML Signing and Verification with KamuSM)

HSM-Signer Service

HSM-Signer Service is an HSM-backed enterprise digital signature platform that unifies KamuSM-compliant XML (XAdES) and PDF (PAdES) signing and verification processes within a single secure infrastructure. The legacy digest-based structure was transformed into a modern, secure, scalable, and compliance-ready solution.

Project Scope

Within the scope of the project, REST-based services were designed and deployed to production to manage signing and verification operations for XML and PDF documents. PKCS#11-based HSM communication ensured secure key isolation, while high performance and availability were maintained under heavy workloads.

Key Outcomes

• 🔐 10,000+ signing/verification operations per day
• ⚡ Approximately 60% higher throughput under peak load
• ⏱️ Signing latency reduced from ~800 ms to ~300 ms
• 🧭 End-to-end tracing with X-Request-ID enabled around 40% faster issue resolution
• 🛡️ 99.9% availability target and strong production resilience

Performance Metrics

Daily transaction volume
██████████ 10K+/day

Peak load throughput
████████░░ +60%

Latency improvement
████████░░ ~60%

Issue resolution speed
██████░░░░ ~40%

Delivered Solution

• /sign for managing general signing workflows
• /sign-xml and /validate-xml for XAdES-based XML operations
• /sign-pdf and /validate-pdf for PAdES-based PDF operations
• /certificate for certificate-based verification workflows
• Secure HSM communication and key isolation via PKCS#11
• Asynchronous queue-based architecture for scalable transaction capacity
• Containerized infrastructure with Docker, suitable for zero-downtime deployments

Architectural Approach

Requests are received at the API layer, routed to the relevant signing or verification workflow, processed securely through the HSM via PKCS#11 integration, and tracked end-to-end through the observability layer. This architecture brings security, performance, and operational traceability together in one solution.

Technical Strengths

• High transaction capacity for enterprise-scale workloads
• Compliance-ready architecture aligned with national e-signature standards
• Production-friendly service design that is maintainable and extensible
• End-to-end request tracing for advanced monitoring and troubleshooting

Result

The final solution not only fulfilled secure digital signing requirements, but also delivered an observable, sustainable, and enterprise-ready digital signature infrastructure capable of handling high transaction volumes with confidence.