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Issue PQC composite certificates

PQC "composite" certificates support both traditional and post-quantum algorithms to help ease the transition to new quantum-safe systems.

Use DigiCert​​®​​ Trust Lifecycle Manager to issue and manage (revoke, suspend/resume, or recover) private PQC composite certificates that combine the post-quantum Dilithium (MLDSA) algorithm with traditional RSA and ECDSA algorithms.

Composite key type

Key size

Signing algorithm

MLDSA-44 + RSA-2048

MLDSA-44_RSA2048-Sha256

MLDSA-44_sha256WithRSA

MLDSA-44 + RSAPSS-2048

MLDSA-44_RSA2048-Sha256Pss

MLDSA-44_sha256WithRSAPss

MLDSA-44 + ECDSA-P256

MLDSA-44_ECDSA-P256

MLDSA-44_sha256WithECDSA

MLDSA-65 + RSA-3072

MLDSA-65_RSA3072-Sha512

MLDSA-65_sha512WithRSA

MLDSA-65 + ECDSA-P256

MLDSA-65_ECDSA-P256

MLDSA-65_sha512WithECDSA

MLDSA-87 + ECDSA-P384

MLDSA-87_ECDSA-P384

MLDSA-87_sha512WithECDSA

Before you begin

You need at least one private issuing CA available in DigiCert® CA Manager.

Avviso

Contact your DigiCert account representative or system administrator if you need help verifying or creating a CA.

Available certificate templates

Use the following base templates to create certificate profiles in Trust Lifecycle Manager for requesting PQC composite certificates from a private issuing CA in DigiCert® CA Manager. Supported enrollment methods include CSR, EST, and REST API.

Create a certificate profile

To create a certificate profile for issuing PQC composite certificates:

  1. From the Trust Lifecycle Manager main menu, select Policies > Certificate profiles.

  2. Select the Create profile from template action at the top of the page.

  3. Select one of the templates from the above table as the basis for creating the certificate profile.

    Work through the profile creation wizard, focusing on the PQC-related options described below and making other selections for your business needs and types of certificates you want to issue. After filling out each screen, select Next to move to the next screen.

  4. On the initial Primary options screen of the profile creation wizard, configure the:

    • General information: Select the applicable business unit and issuing CA for the certificates.

    • Enrollment method: Select one of the following.

      • CSR to enroll from a CSR using a web-based enrollment flow.

      • EST to enroll from a remote client using the EST protocol (not available for S/MIME certificates).

      • REST API to enroll from a CSR using the Trust Lifecycle Manager REST API.

    • Authentication method: Select one of the available authentication methods for the enrollment method you selected.

  5. On the Certificate options screen:

    • Key type: Select COMPOSITE.

    • Key sizes: Select one or more key sizes to allow for enrolling PQC composite certificates.

  6. On the Additional options screen:

    • Certificate delivery format: Select whether to deliver certificates in X.509 or PKCS#7 format. For PKCS#7, select an option for how to include the CA chain.

  7. Select Create to save the new certificate profile.

CSRs and private keys for testing

Use these example CSRs to test issuance of PQC composite certificates via the DigiCert​​®​​ Trust Lifecycle Manager API or web-based enrollment.

Select the links to download each CSR file and its corresponding private key in PEM-encoded format.

Test PQC composite issuance via web-based enrollment

Follow these steps to test issuance of PQC composite certificates from a CSR via web-based enrollment using one of the supported authentication methods.

Before you begin

  • Create a certificate profile for PQC composite certificates (key type COMPOSITE) that uses the CSR enrollment method and one of the supported authentication methods (for example, Manual approval). Copy the Enrollment URL generated when saving the profile.

  • Download a testing CSR from the above table for one of the allowed Key sizes you configured in the PQC composite certificate profile.

Request a PQC certificate

  1. Use a web browser to access the Enrollment URL for the PQC certificate profile you created. You can get this URL from the profile details page, or from the self-service portal if enabled.

  2. Complete the enrollment form and upload the testing CSR you downloaded from the above table.

  3. Select Submit to submit the enrollment request.

Approve the enrollment request

  1. Log into Trust Lifecycle Manager as a user with the Manager or User and certificate manager role.

  2. Use one of the following methods to load the pending enrollment requests:

    • Select Enrollments from the Trust Lifecycle Manager main menu. Filter the list as needed.

    • On the Dashboard page, in the Pending requests widget, select the numbered link under Pending approval to load the pending enrollments.

  3. Find the pending enrollment for the PQC certificate request. Select the seat ID to review the enrollment before approving, or to approve immediately open the actions (icon) menu and select Approve.

Download the certificate

  1. After approving the enrollment request, an email is sent to the requester address with a download link.

  2. Select the link in the confirmation email and follow the instructions to download the new PQC certificate.