ZyXEL P-661H-D1 User Guide - Page 208

Certification Path, Certificate Directory Servers, Advantages of Certificates

Page 208 highlights

Chapter 15 Certificates 3 Tim uses his private key to encrypt the message and sends it to Jenny. 4 Jenny receives the message and uses Tim's public key to decrypt it. 5 Additionally, Jenny uses her own private key to encrypt a message and Tim uses Jenny's public key to decrypt the message. The ZyXEL Device uses certificates based on public-key cryptology to authenticate users attempting to establish a connection. The method used to secure the data that you send through an established connection depends on the type of connection. For example, a VPN tunnel might use the triple DES encryption algorithm. The certification authority uses its private key to sign certificates. Anyone can then use the certification authority's public key to verify the certificates. Certification Path A certification path is the hierarchy of certification authority certificates that validate a certificate. The ZyXEL Device does not trust a certificate if any certificate on its path has expired or been revoked. Certificate Directory Servers 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 A directory of certificates that have been revoked before the scheduled expiration is called a CRL (Certificate Revocation List).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). Advantages of Certificates 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. Certificate File Formats The certification authority certificate that you want to import has to be in one of these file formats: 208 P-661HNU-Fx User's Guide

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Chapter 15 Certificates
P-661HNU-Fx User’s Guide
208
3
Tim uses his private key to encrypt the message and sends it to Jenny.
4
Jenny receives the message and uses Tim’s public key to decrypt it.
5
Additionally, Jenny uses her own private key to encrypt a message and Tim uses
Jenny’s public key to decrypt the message.
The ZyXEL Device uses certificates based on public-key cryptology to authenticate
users attempting to establish a connection. The method used to secure the data
that you send through an established connection depends on the type of
connection. For example, a VPN tunnel might use the triple DES encryption
algorithm.
The certification authority uses its private key to sign certificates. Anyone can then
use the certification authority’s public key to verify the certificates.
Certification Path
A certification path is the hierarchy of certification authority certificates that
validate a certificate. The ZyXEL Device does not trust a certificate if any
certificate on its path has expired or been revoked.
Certificate Directory Servers
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).
Advantages of Certificates
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.
Certificate File Formats
The certification authority certificate that you want to import has to be in one of
these file formats: