Client Authentication Certificates
Only authorized devices and users get in — cryptographically enforced
Client Authentication Certificates provide machine-level identity for devices, servers, and users accessing enterprise networks, cloud platforms, and operational systems. Unlike passwords, certificates can't be phished, shared, or guessed.
Certificate-based access control for machines, devices, and users
A Client Authentication Certificate is an X.509 digital certificate with the clientAuth extended key usage flag. When a client presents this certificate during a TLS handshake, the server can cryptographically verify the client’s identity before granting access.
This is the foundation of zero-trust network architectures — mutual TLS (mTLS), where both sides of a connection prove their identity before any data is exchanged.
Key benefits
Phishing-resistant authentication
The private key never leaves the device — nothing to steal via phishing or credential dumping.
Per-device identity
Each device gets a unique certificate — access can be granted or revoked per device.
Mutual TLS (mTLS)
Both client and server authenticate each other — the foundation of zero-trust architecture.
API-driven issuance
Issue certificates at scale during manufacturing or provisioning via REST API.
Enterprise-grade PKI
Backed by SSL.com's WebTrust-audited CA infrastructure, annually reviewed by BDO.
Broad compatibility
Compatible with all major TLS stacks, VPN solutions, and network access control systems.
Revocable
Compromised or retired devices can have certificates revoked — access terminated immediately.
Who is it for?
IoT device manufacturers
Provisioning unique identity to each device at the factory.
Enterprise IT / security teams
Enforcing certificate-based VPN and network access.
OT / SCADA engineers
Authenticating operator workstations to industrial control systems.
DevOps / platform engineering
Implementing mTLS for service-to-service API security.
Energy sector organizations
NAESB-compliant client certificates for market transactions.
Zero-trust architects
Replacing password-based access with cryptographic identity.
Purchase
1 Select certificate
2 Select duration
Order Summary
How it works
Purchase
Select your certificate type and duration, then complete your order.
Validation
SSL.com validates the requesting entity (email, domain, or organization).
Certificate issued
Certificate is generated and delivered. Install on the target device or workstation.
Configure your system
Configure your server, VPN, or NAC to require and validate client certificates.
Authenticate
Connecting clients present their certificate — the server validates and grants or denies access.
Compatibility
All major TLS stacks
OpenSSL, BoringSSL, Schannel, SecureTransport — any TLS 1.2/1.3 implementation.
VPN platforms
Cisco AnyConnect, Palo Alto GlobalProtect, Fortinet FortiClient, OpenVPN.
Network Access Control
Cisco ISE, Aruba ClearPass, Microsoft NPS/RADIUS — 802.1X authentication.
API gateways
Kong, AWS API Gateway, Azure API Management, NGINX — mTLS support.
Industrial control systems
Siemens, Rockwell, Schneider Electric SCADA — IEC 62443 profiles.
Compliance & standards
clientAuth EKU per X.509 standard.
SSL.com is NAESB-accredited.
mTLS is a foundational zero-trust control.
Industrial automation security.
Critical infrastructure access control.
SSL.com audited annually.
Frequently asked questions
Related products
Matter DAC
Cryptographic identity for Matter-certified IoT devices.
NAESB WEQ-12
Energy sector market participation certificates.
Managed PKI
Enterprise-scale certificate management.
