ZyWALL 2 Plus User’s Guide
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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.
When using public-key cryptology for authentication, 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-private 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. 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been revoked.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 ADSL 2+ Security Gateway
Page 2: ......
Page 25: ...Table of Contents ZyWALL 2 Plus User s Guide 25 Index 679 ...
Page 26: ...Table of Contents ZyWALL 2 Plus User s Guide 26 ...
Page 46: ...46 ...
Page 88: ...Chapter 3 Wizard Setup ZyWALL 2 Plus User s Guide 88 ...
Page 132: ...132 ...
Page 144: ...Chapter 6 LAN Screens ZyWALL 2 Plus User s Guide 144 ...
Page 180: ...Chapter 9 DMZ Screens ZyWALL 2 Plus User s Guide 180 ...
Page 190: ...190 ...
Page 222: ...Chapter 11 Firewall ZyWALL 2 Plus User s Guide 222 ...
Page 252: ...Chapter 13 Content Filtering Reports ZyWALL 2 Plus User s Guide 252 ...
Page 328: ...Chapter 16 Authentication Server ZyWALL 2 Plus User s Guide 328 ...
Page 330: ...330 ...
Page 346: ...Chapter 17 Network Address Translation NAT ZyWALL 2 Plus User s Guide 346 ...
Page 350: ...Chapter 18 Static Route ZyWALL 2 Plus User s Guide 350 ...
Page 398: ...Chapter 21 Remote Management ZyWALL 2 Plus User s Guide 398 ...
Page 416: ...Chapter 24 ALG Screen ZyWALL 2 Plus User s Guide 416 ...
Page 417: ...417 PART V Logs and Maintenance Logs Screens 419 Maintenance 447 ...
Page 418: ...418 ...
Page 423: ...Chapter 25 Logs Screens ZyWALL 2 Plus User s Guide 423 Figure 274 LOGS Log Settings ...
Page 466: ...466 ...
Page 474: ...Chapter 27 Introducing the SMT ZyWALL 2 Plus User s Guide 474 ...
Page 496: ...Chapter 30 LAN Setup ZyWALL 2 Plus User s Guide 496 ...
Page 504: ...Chapter 32 DMZ Setup ZyWALL 2 Plus User s Guide 504 ...
Page 508: ...Chapter 33 Wireless Setup ZyWALL 2 Plus User s Guide 508 ...
Page 556: ...Chapter 38 Filter Configuration ZyWALL 2 Plus User s Guide 556 ...
Page 570: ...Chapter 40 System Information Diagnosis ZyWALL 2 Plus User s Guide 570 ...
Page 586: ...Chapter 41 Firmware and Configuration File Maintenance ZyWALL 2 Plus User s Guide 586 ...
Page 594: ...Chapter 42 System Maintenance Menus 8 to 10 ZyWALL 2 Plus User s Guide 594 ...
Page 598: ...Chapter 43 Remote Management ZyWALL 2 Plus User s Guide 598 ...
Page 604: ...604 ...
Page 612: ...Chapter 45 Troubleshooting ZyWALL 2 Plus User s Guide 612 ...
Page 620: ...620 ...
Page 644: ...Appendix B Pop up Windows JavaScripts and Java Permissions ZyWALL 2 Plus User s Guide 644 ...
Page 668: ...Appendix E Importing Certificates ZyWALL 2 Plus User s Guide 668 ...
Page 672: ...Appendix F Legal Information ZyWALL 2 Plus User s Guide 672 ...
Page 678: ...Appendix G Customer Support ZyWALL 2 Plus User s Guide 678 ...