DuoKey

Swiss energy operator · Energy · Critical infrastructure

Board papers protected with a key Microsoft does not hold.

A Swiss critical-infrastructure operator in the energy sector uses DuoKey Double Key Encryption to keep its board's most sensitive documents in Microsoft 365, with the second key under its own control.

The problem

The board works in Microsoft 365 like the rest of the company. Strategy, grid security and regulatory files are critical-infrastructure information. With standard cloud encryption the provider can still decrypt them, including in response to a foreign legal request.

How DuoKey helps

DuoKey adds a second key held outside Microsoft. Board content labelled for Double Key Encryption opens in Word, Excel, PowerPoint and Outlook for authorised members, and stays unreadable to the cloud provider.

How it works

Step by step, where the keys go

Microsoft 365KEY 1DuoKeyKEY 2 · OPERATORBoard · DKEAuthorised memberWORD · EXCEL · OUTLOOKProvider accessSTAYS LOCKEDKEY LOG09:41 opened09:42 denied
  1. 01 / 04

    The board label is applied

    A board paper in Word, Excel or PowerPoint gets the dedicated board sensitivity label. Nothing else changes for the author.

  2. 02 / 04

    Two keys lock the document

    The content is encrypted with a Microsoft key and a second key held by DuoKey for the operator. Both are needed to open it.

  3. 03 / 04

    An authorised member opens it

    For a board member, both keys are released and the document opens in the usual Office app. DuoKey records the key request.

  4. 04 / 04

    The provider alone cannot

    Microsoft, or anyone presenting a legal request to Microsoft, holds only the first key. The document stays locked and the refusal is on record.

Security leadership

The questions this programme had to answer

What changed

How DuoKey protects board information in Microsoft 365

  • DKE

    Second key outside the cloud

    Protected board documents need a key that Microsoft never holds.

  • Board

    Protection scoped to the people who need it

    A dedicated sensitivity label covers board material without changing how the rest of the company works.

  • M365

    The board keeps its tools

    Members read and edit protected files in the Office apps they already use.

  • Proof

    Key use recorded independently

    Every decryption request is logged by DuoKey, outside Microsoft's own audit trail.

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