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#access-control

Log entries with this tag, newest first.

  1. Decision recordDevices at the edge

    Panel passwords are sealed to the host that uses them

    A secret that one process uses should be readable by that process alone. The decision record for the administrator passwords of access-control panels: write-only entry, a fresh AES-GCM key per secret wrapped with RSA-OAEP under the connector host's key, opened in memory only, one escrow export and then a key nobody can export, a TPM tier that excludes escrow, and why machine-scope DPAPI and the web runtime's key ring were the wrong tools.

    16 Oct 2026 · 8 min read

  2. Field noteDevices at the edge

    Talking to door controllers: what ISAPI teaches about typed outcomes

    A boolean cannot carry what an access-control panel answers. Three measured facts (a failed write with HTTP 200 and no status, an acknowledged write that changed nothing, a reused digest nonce the panel refused) turned a 27-member interface whose every write returned a boolean into a closed set of typed outcomes, a classification order, a read-back rule and a fresh challenge per request; asking which way a door fails added a deadline on anything that unlocks one.

    16 Oct 2026 · 9 min read

Dejan Demonjić

Designing and building secure, multi-tenant .NET platforms, and writing down the decisions behind them.

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© Dejan Demonjić. Written in Belgrade.