ZyWALL 35 User’s Guide
Chapter 15 Certificates
265
C
H A P T E R
15
Certificates
This chapter gives background information about public-key certificates and explains how to
use them.
15.1 Certificates Overview
The ZyWALL can use certificates (also called digital IDs) to authenticate users. Certificates
are based on public-private key pairs. A certificate contains the certificate owner’s identity and
public key. Certificates provide a way to exchange public keys for use in authentication.
A Certification Authority (CA) issues certificates and guarantees the identity of each
certificate owner. There are commercial certification authorities like CyberTrust or VeriSign
and government certification authorities. You can use the ZyWALL to generate certification
requests that contain identifying information and public keys and then send the certification
requests to a certification authority.
In public-key encryption and decryption, each host has two keys. One key is public and can be
made openly available; the other key is private and must be kept secure. Public-key encryption
in general works as follows.
1
Tim wants to send a private message to Jenny. Tim generates a public key pair. What is
encrypted with one key can only be decrypted using the other.
2
Tim keeps the private key and makes the public key openly available.
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 ZyWALL uses certificates based on public-key cryptology to authenticate users
attempting to establish a connection, not to encrypt the data that you send after establishing 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.
A certification path is the hierarchy of certification authority certificates that validate a
certificate. The ZyWALL does not trust a certificate if any certificate on its path has expired or
been revoked.
Summary of Contents for ZyXEL ZyWALL 35
Page 1: ...ZyWALL 35 Internet Security Appliance User s Guide Version 3 64 3 2005 ...
Page 2: ......
Page 38: ...ZyWALL 35 User s Guide 36 ...
Page 46: ...ZyWALL 35 User s Guide 44 ...
Page 74: ...ZyWALL 35 User s Guide 72 Chapter 2 Introducing the Web Configurator ...
Page 90: ...ZyWALL 35 User s Guide 88 Chapter 3 Wizard Setup ...
Page 100: ...ZyWALL 35 User s Guide 98 Chapter 4 LAN Screens ...
Page 106: ...ZyWALL 35 User s Guide 104 Chapter 5 Bridge Screens ...
Page 128: ...ZyWALL 35 User s Guide 126 Chapter 6 Wireless LAN ...
Page 135: ...ZyWALL 35 User s Guide Chapter 7 WAN Screens 133 Figure 47 General ...
Page 152: ...ZyWALL 35 User s Guide 150 Chapter 7 WAN Screens Figure 57 Dial Backup Setup ...
Page 158: ...ZyWALL 35 User s Guide 156 Chapter 7 WAN Screens ...
Page 166: ...ZyWALL 35 User s Guide 164 Chapter 8 DMZ Screens ...
Page 234: ...ZyWALL 35 User s Guide 232 Chapter 13 Introduction to IPSec ...
Page 275: ...ZyWALL 35 User s Guide Chapter 15 Certificates 273 Figure 129 My Certificate Details ...
Page 294: ...ZyWALL 35 User s Guide 292 Chapter 16 Authentication Server Figure 140 Local User Database ...
Page 314: ...ZyWALL 35 User s Guide 312 Chapter 17 Network Address Translation NAT ...
Page 318: ...ZyWALL 35 User s Guide 316 Chapter 18 Static Route ...
Page 324: ...ZyWALL 35 User s Guide 322 Chapter 19 Policy Route ...
Page 340: ...ZyWALL 35 User s Guide 338 Chapter 20 Bandwidth Management ...
Page 376: ...ZyWALL 35 User s Guide 374 Chapter 22 Remote Management ...
Page 390: ...ZyWALL 35 User s Guide 388 Chapter 24 Logs Screens Figure 198 Log Settings ...
Page 413: ...ZyWALL 35 User s Guide Chapter 25 Maintenance 411 Figure 220 Restart Screen ...
Page 414: ...ZyWALL 35 User s Guide 412 Chapter 25 Maintenance ...
Page 440: ...ZyWALL 35 User s Guide 438 Chapter 28 WAN and Dial Backup Setup ...
Page 456: ...ZyWALL 35 User s Guide 454 Chapter 31 DMZ Setup ...
Page 460: ...ZyWALL 35 User s Guide 458 Chapter 32 Route Setup ...
Page 470: ...ZyWALL 35 User s Guide 468 Chapter 33 Remote Node Setup ...
Page 522: ...ZyWALL 35 User s Guide 520 Chapter 39 System Information Diagnosis ...
Page 538: ...ZyWALL 35 User s Guide 536 Chapter 40 Firmware and Configuration File Maintenance ...
Page 550: ...ZyWALL 35 User s Guide 548 Chapter 42 Remote Management ...
Page 558: ...ZyWALL 35 User s Guide 556 Chapter 43 IP Policy Routing ...
Page 574: ...ZyWALL 35 User s Guide 572 Chapter 45 Troubleshooting Figure 364 Java Sun ...
Page 602: ...ZyWALL 35 User s Guide 600 Appendix C IP Subnetting ...
Page 608: ...ZyWALL 35 User s Guide 606 Appendix E PPTP ...
Page 626: ...ZyWALL 35 User s Guide 624 Appendix G Triangle Route ...
Page 656: ...ZyWALL 35 User s Guide 654 Appendix J Importing Certificates ...
Page 658: ...ZyWALL 35 User s Guide 656 Appendix K Command Interpreter ...
Page 664: ...ZyWALL 35 User s Guide 662 Appendix L Firewall Commands ...
Page 668: ...ZyWALL 35 User s Guide 666 Appendix M NetBIOS Filter Commands ...
Page 674: ...ZyWALL 35 User s Guide 672 Appendix O Brute Force Password Guessing Protection ...
Page 696: ...ZyWALL 35 User s Guide 694 Appendix Q Log Descriptions ...