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Information for Auditors and Assessors

To increase trust in the application of PKI technology, the CA/Browser Forum has mandated that a CA, in order to issue Publicly-Trusted Certificates, obtain an audit report under a qualified audit scheme performed by a qualified auditor.

In order to issue SSL certificates, most CAs will need to complete an approved independent third-party audit. There are three alternatives. The first is an audit against WebTrust for Certification Authorities criteria, issued by the WebTrust for Certification Authorities Task Force-a joint task force of the American Institute of Certified Public Accountants and the Chartered Professional Accountants of Canada (CPA Canada). Specifically, WebTrust for Certification Authorities and WebTrust for Certification Authorities – SSL Baseline Requirements Audit Criteria have been developed to meet the CA/Browser Forums Baseline SSL Requirements.

Another alternative for an independent third-party audit is an audit that conforms to ETSI EN 319 411-1 or ETSI EN 319 411-2. These standards are published by the European Telecommunications Standards Institute (ETSI).

Also available, but rarely used is an audit that conforms to ISO 21188:2006.

In addition, recognizing the importance of an independent third party audit of the controls, processes and procedures of CAs, the CA/Browser Forum’s EV Guidelines include a specific audit requirement for CAs that wish to issue EV certificates.

A non-governmental CA issuing EV Certificates needs to undergo an audit in accordance either the WebTrust for Certification Authorities audit and the WebTrust EV Program audit, or the ETSI EN 319 411-1 audit.

Latest releases
Server Certificate Requirements
SC098: Process RFC 8657 CAA Parameters - Jun 16, 2026

Code Signing Requirements
v3.8 - Aug 5, 2024

What’s Changed CSC-25: Import EV Guidelines to CS Baseline Requirements by @dzacharo in https://github.com/cabforum/code-signing/pull/38 Full Changelog: https://github.com/cabforum/code-signing/compare/v3.7...v3.8

S/MIME Requirements
v1.0.15 - Ballot SMC017v2 - Jul 30, 2026

This ballot increases the minimum RSA key size for Root and Subordinate CA certificates in the S/MIME BRs from 2048 to 4096 bits for keys created after September 15, 2026, while retaining the 2048-bit minimum for Subscriber certificates. The ballot further requires that by September 15, 2027, CAs SHALL NOT issue Subscriber certificates from any Sub-CA whose RSA key modulus is less than 3072 bits, effectively sunsetting issuance from legacy 2048-bit Sub-CAs. The ballot also includes minor typographic corrections. This ballot is proposed by Martijn Katerbarg (Sectigo) and endorsed by Ben Wilson (Mozilla) and Stephen Davidson (DigiCert)

Network and Certificate System Security Requirements
Version 2.0.5 (Ballot NS-008) - Jul 9, 2025

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The Certification Authority Browser Forum (CA/Browser Forum) is a voluntary gathering of Certificate Issuers and suppliers of Internet browser software and other applications that use certificates (Certificate Consumers).