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Operational limits

This page captures practical limits and expectations for Pico OpenPGP operations.


Performance profile

Operation time depends on algorithm and key size.

In general:

  • ECC operations are faster
  • Larger RSA keys increase latency significantly

Plan UX and automation timeouts accordingly, especially for high-bit RSA workflows.


Tooling limitations

Not every client tool exposes every card capability.

For some advanced operations, support may depend on:

  • specific middleware versions
  • PKCS#11 module behavior
  • direct APDU tooling

UI availability is not always equivalent to firmware capability availability.

If a feature appears missing in one client, verify with an alternative tool path before concluding firmware regression.


Environment dependencies

Runtime behavior is affected by:

  • host OS smart-card stack
  • PC/SC service state
  • USB reader/device recognition
  • board/firmware configuration choices

Treat these dependencies as part of deployment validation, not as optional post-setup checks.


Capacity and workflow planning

For reliable operations in production-like environments:

  • Prefer ECC when latency matters.
  • Reserve large RSA key operations for explicit cases that require them.
  • Budget time for unlock/retry/recovery flows in automation pipelines.
  • Separate “fast path” daily operations from “maintenance path” admin operations.

Troubleshooting priority order

When operations fail or are unexpectedly slow, use this order:

  1. Confirm device/session state (connected, unlocked, correct role context).
  2. Confirm host middleware health (PC/SC, reader visibility).
  3. Re-test with a second client/tooling path.
  4. Then inspect firmware-specific behavior.

This ordering reduces false positives and shortens incident triage time.