ZyXEL Communications NWA3160 User Manual

Chapter 16 Certificates

ZyXEL NWA-3160 Series User’s Guide

Certification authorities maintain directory servers with databases of valid and revoked 
certificates. A directory of certificates that have been revoked before the scheduled expiration 
is called a CRL (Certificate Revocation List). The ZyXEL Device can check a peer’s 
certificate against a directory server’s list of revoked certificates. The framework of servers, 
software, procedures and policies that handles keys is called PKI (public-key infrastructure).

Certificates offer the following benefits.

• The ZyXEL Device only has to store the certificates of the certification authorities that 

you decide to trust, no matter how many devices you need to authenticate. 

• Key distribution is simple and very secure since you can freely distribute public keys and 

you never need to transmit private keys.

 You can have the ZyXEL Device act as a certification authority and sign its own certificates.

Before you import a trusted CA certificate into the ZyXEL Device, you should verify that you 
have the actual certificate. This is especially important since the ZyXEL Device also trusts any 
valid certificate signed by any of the imported trusted CA certificates.

A certificate’s fingerprints are message digests calculated using the MD5 or SHA1 algorithms. 
The following procedure describes how to check a certificate’s fingerprint to verify that you 
have the actual certificate. 

1 Browse to where you have the certificate saved on your computer. 
2 Make sure that the certificate has a “.cer” or “.crt” file name extension.

Figure 113   Certificates on Your Computer

3 Double-click the certificate’s icon to open the Certificate window. Click the Details tab 

and scroll down to the Thumbprint Algorithm and Thumbprint fields.