DuoKey + Securosys: HSM Integration for Microsoft 365 DKE, PKI and PQC

DuoKey and Securosys are partners, not competitors. Securosys builds Swiss hardware security modules (Primus HSM) and runs them as a managed service (Securosys CloudHSM). DuoKey is the key management layer above them: DuoKey Cockpit connects to a Securosys HSM as a vault, then uses the keys held there for Microsoft 365 Double Key Encryption (DKE), certificate authorities, database encryption and post-quantum keys. The key material stays inside the Securosys HSM.

This page explains what each product does, the architectures that combine them, and how to decide which one you need. Securosys facts come from Securosys's own website and documentation, reviewed in November 2026. DuoKey facts come from docs.duokey.com.

---

Table of Contents

1. The partnership in short
2. What Securosys provides
3. What DuoKey provides
4. Securosys DKE for Microsoft 365
5. Architectures that combine DuoKey and Securosys
6. Looking for a Securosys alternative? When to choose what
7. FAQ
8. Sources

---

The partnership in short

• Listed partner. Securosys appears on DuoKey's partner list, and DuoKey's documentation names Securosys as Cockpit's "lead hardware security module partner" (DuoKey docs: Platform capabilities).
• Shared history in Microsoft 365. On 16 February 2021, DuoKey and Securosys announced Securosys 365 Double Key Encryption, provided through Securosys's ISO 27001-certified CloudsHSM service in Switzerland and "operated geo-redundantly in three different Swiss datacenters" (startupticker.ch, 16 February 2021).
• One integration today. In DuoKey Cockpit, a Securosys vault connects to a Primus HSM on premises or to Securosys CloudHSM through Securosys's Transaction Security Broker (TSB) REST API (DuoKey docs: Securosys HSM).

What Securosys provides

Securosys is a Swiss HSM manufacturer based in Zurich. Its products relevant here:

Primus HSM. A network HSM appliance. Securosys documents these certifications (Securosys docs: Standards & Certifications):

• FIPS 140-2 Level 3 for firmware 2.5.14 (certificates #4583 and #3430). FIPS 140-3 Level 3 for firmware 3.1.0 is listed as "certification in progress", under NIST evaluation since December 2024.
• Common Criteria EAL4+ under SOG-IS, for firmware 2.8.21, 2.8.22 and 3.1.0.
• Compliance with the eIDAS protection profile EN 419 221-5, with QSCD certificates listed for the same firmware versions.

The supported APIs are JCA/JCE, Microsoft CNG, PKCS#11 and REST through the Transaction Security Broker (Securosys docs: Primus HSM overview). Securosys states that its firmware from v3.x supports ML-KEM, ML-DSA and SLH-DSA, plus the stateful hash-based signatures HSS-LMS and XMSS (Securosys: Post-quantum cryptography).

Securosys CloudHSM. A fully managed HSM service running on Primus HSMs, offered as dedicated or shared multi-tenant HSMs, with access points in Switzerland, Germany, Singapore and the US. Securosys lists PKCS#11, OpenSSL, JCE/JCA, Microsoft CNG and REST as interfaces, and states that it "has no access to customer data" (Securosys: CloudHSM).

Securosys 365 DKE. A managed Double Key Encryption service for Microsoft 365, with the customer key protected in Securosys CloudHSM. See Securosys DKE for Microsoft 365 below.

What DuoKey provides

DuoKey Cockpit is one console and API over many key backends. Every backend exposes the same operations (create, rotate, destroy, encrypt, decrypt, sign, verify, wrap, unwrap), and backend credentials are stored encrypted per tenant, so each tenant can bind its own HSM (DuoKey docs: Platform capabilities).

DuoKey's documentation describes the Securosys vault as the most complete backend (DuoKey docs: Securosys HSM operations):

• Core operations: create, delete, get public key, encrypt and decrypt (AES-GCM and RSA-OAEP), sign and verify.
• Signing algorithms: RSA (PKCS#1 v1.5 and PSS with SHA-256), ECDSA (SHA-256), HMAC-SHA256, and the post-quantum ML-DSA and SLH-DSA families, signed in the HSM.
• Key wrapping: wrap and unwrap for key export and import between HSM keys.
• Certificates: CSR generation, self-signing and certificate import against HSM-held keys.
• Entropy and health: hardware random generation, plus licence, version and keystore statistics. A test-connection action checks TSB connectivity and the token before you bind applications.

On top of the vault, Cockpit adds what an HSM does not do on its own: a DKE endpoint for Microsoft 365, access policies on every decrypt, quorum approvals, certificate lifecycle, cryptographic inventory and a hash-chained audit log. DuoKey also offers an MPC vault, where each key is split into shares on independent nodes and no single node holds the complete key. For the trade-offs between the two custody models, see MPC vs HSM key management.

Securosys DKE for Microsoft 365

DKE protects the most sensitive Microsoft 365 content with two keys: one in Microsoft Azure, one held outside Microsoft. Content opens only when both are available. There are two ways to put a Securosys HSM behind that second key.

Securosys 365 DKE. Securosys sells a "Fully Managed DKEaaS". The customer-controlled key is protected in Securosys CloudHSM, encryption is triggered by Microsoft Purview sensitivity labels, and Securosys lists Microsoft 365 E5 licences as a prerequisite (Securosys: DKE for Microsoft 365). This is the direct route when you want one vendor for both the DKE service and the HSM.

DuoKey DKE with a Securosys vault. In DuoKey Cockpit, the DKE wizard starts by selecting a vault and an RSA-2048 key from it (the Microsoft DKE client requires RSA-2048). Cockpit then runs a preflight with a wrap and unwrap round trip before the service is deployed (DuoKey docs: Deploy a DKE service). Choose a Securosys vault in that step and the DKE private key stays in the Securosys HSM, while Cockpit provides:

• an access policy checked on each decrypt (user, group, IP range, country, time);
• key rotation with a cache window, so the previous key keeps serving requests while labels move to the new one;
• the Entra ID app registration provisioned for you;
• the same console for your other key integrations.

For the DKE model itself, read What is Double Key Encryption. For DuoKey's DKE product, see DuoKey for Microsoft 365 DKE.

Customer Key. Microsoft 365 Customer Key (service encryption) is a different mechanism: root keys live in Azure Key Vault. DuoKey supports it through a documented BYOK process, where the key is generated offline, wrapped for transport under Azure Key Vault key-encryption keys and imported as a BYOK file (DuoKey docs: Customer Key BYOK process).

Architectures that combine DuoKey and Securosys

1. Securosys HSM as a Cockpit vault

The base pattern. Cockpit holds the TSB endpoint and credentials per tenant, applications call Cockpit, and Cockpit calls the HSM. Keys are created in the Primus HSM or in CloudHSM and never leave it in plaintext. Everything built on Cockpit can then use those keys: DKE, certificate authorities, Oracle TDE, AWS XKS and others.

2. Certificate authorities and post-quantum keys in the HSM

A CA created in DuoKey with a Securosys vault keeps its signing key in the HSM and signs certificates, CRLs and OCSP responses there. Because the Securosys vault signs ML-DSA and SLH-DSA in hardware, a post-quantum or hybrid CA can be bound to it (DuoKey docs: Securosys HSM). With a Securosys Primus vault, CA keys can also use RSA-3072, RSA-8192 and EC P-521 (DuoKey docs: PKI key algorithms). More in the ML-DSA certificates guide.

3. PKCS#11: databases and secret managers

Two PKCS#11 paths are documented:

• Through DuoKey's PKCS#11 library. Oracle TDE loads the DuoKey PKCS#11 provider, which sends master-key operations to Cockpit. For hardware custody, the vault behind it is a Securosys HSM (DuoKey docs: Oracle TDE overview). See the Oracle TDE external keystore guide.
• Directly to the HSM. In DuoKey's on-premises deployment, OpenBao or Vault seals and unseals against the Securosys HSM over PKCS#11 or KMIP, so the master key never exists in plaintext outside the HSM boundary (DuoKey docs: Secret Manager Integration). The OpenBao auto-unseal guide compares seal options.

4. MPC and HSM side by side

DuoKey's documentation states that "MPC and the HSM can be combined for defense-in-depth" (DuoKey docs: Secret Manager Integration). In practice that means choosing custody per key under one console and one audit log: keys that must sit in certified hardware (for example a CA root or keys under an eIDAS requirement) go in the Securosys vault, and keys where no single location should hold the complete key go in the MPC vault. Applications see the same Cockpit API either way.

5. Inventory of HSM keys

DuoKey's cryptographic posture management reads keys from Securosys HSMs as part of its inventory, so HSM keys appear next to cloud KMS keys, certificates and code findings when you plan a post-quantum migration (DuoKey docs: Data sources).

Looking for a Securosys alternative? When to choose what

People who search for a "Securosys alternative" are often asking one of two different questions. The honest answer depends on which one.

DuoKey is not a replacement for a certified HSM. If a regulation or an auditor requires keys inside FIPS or Common Criteria certified hardware, keep the HSM, and use DuoKey for the policy, integration and lifecycle work around it. If what you need is key control for SaaS and cloud workloads, and no rule asks for hardware, DuoKey's MPC vault can hold the keys without an HSM.

FAQ

Is DuoKey a competitor of Securosys? No. Securosys is a DuoKey partner and Cockpit's lead HSM partner. Securosys supplies the hardware root of trust; DuoKey supplies the key management, integrations and policy layer that can run on top of it.

Can DuoKey use a Securosys HSM for Microsoft 365 DKE? Yes. The DKE wizard in DuoKey Cockpit binds an RSA-2048 key from a vault you select. With a Securosys vault, the DKE key stays in the Primus HSM or in Securosys CloudHSM, and Cockpit enforces the access policy on each decrypt.

What is the difference between Securosys 365 DKE and DuoKey DKE? Securosys 365 DKE is Securosys's managed DKE service with the key in its CloudHSM. DuoKey DKE is deployed from DuoKey Cockpit, with the key in the vault you choose (Securosys HSM, MPC or another backend), per-decrypt access policies and rotation with a cache window. Both keep the second key outside Microsoft.

How does DuoKey connect to a Securosys HSM? Cockpit's Securosys vault uses Securosys's Transaction Security Broker (TSB) REST API, for a Primus HSM on premises or Securosys CloudHSM. In on-premises deployments, OpenBao or Vault can also seal against the HSM over PKCS#11 or KMIP.

Does the combination support post-quantum keys? Yes. Securosys states that firmware v3.x supports ML-KEM, ML-DSA and SLH-DSA. DuoKey's Securosys vault signs with ML-DSA and SLH-DSA in the HSM, which lets a post-quantum or hybrid CA keep its signing key in hardware.

Do I need an HSM to use DuoKey? No. Cockpit also offers a software vault, an MPC vault and cloud KMS backends. Add a Securosys HSM when policy or certification requires a hardware root of trust.

Sources

• startupticker.ch, "DuoKey and Securosys secure Microsoft 365", 16 February 2021: startupticker.ch/en/news/duokey-and-securosys-secure-microsoft-365
• Securosys docs, Primus HSM Standards & Certifications: docs.securosys.com/primus-hsm/Overview/compliance
• Securosys docs, Primus HSM overview: docs.securosys.com/primus-hsm/overview
• Securosys, CloudHSM: securosys.com/en/cloudshsm
• Securosys, Post-quantum cryptography: securosys.com/en/hsm/post-quantum-cryptography
• Securosys, DKE for Microsoft 365: securosys.com/en/solution/dke-microsoft365
• DuoKey docs, Securosys HSM vault: docs.duokey.com/docs/cockpit/vaults/securosys
• DuoKey docs, Deploy a DKE service: docs.duokey.com/docs/double-key-encryption/setup/dke-service-deployment
• DuoKey docs, Secret Manager Integration (Securosys HSM): docs.duokey.com/docs/openshift-on-prem/security/secrets-management