Account certification Service (ACS)
What is it?
The Account Certification Service (ACS) is a critical component of the Windows Rights Management Services (RMS) infrastructure. It acts as a certification authority for user accounts, issuing digital certificates known as RM account certificates.
Purpose:
These RM account certificates are essential for authenticating users and enabling them to consume, create, or share protected content within an RMS-enabled environment. The certificates confirm the identity of the user and bind it to a cryptographic key pair.
How it works:
- User Registration: When a user first attempts to access RMS-protected content, their client requests an RM account certificate from the ACS.
- Certificate Issuance: The ACS verifies the user’s identity (often by interacting with Active Directory or another identity provider) and issues a certificate that includes the user’s identity and public key.
- Certificate Distribution: The certificate is securely sent back to the user’s device and stored locally.
- Content Access: When the user attempts to open RMS-protected documents or emails, their client uses the RM account certificate to decrypt the content’s keys and enforce usage rights.
- Renewal and Revocation: ACS manages certificate lifecycle, including renewals, expirations, and revocations to maintain security.
Why is it important?
- Security: Ensures only authorized users can access sensitive or protected data.
- User Identity Binding: Links user identity to encryption keys, enabling fine-grained access control.
- Scalability: Supports large organizations by automating certificate issuance and management.
- Integration: Works seamlessly with Active Directory and other identity providers for authentication.