P-662H/HW-D Series User’s Guide
Chapter 17 Certificates
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C
H A P T E R
17
Certificates
This chapter gives background information about public-key certificates and explains how to
use them.
17.1 Certificates Overview
The ZyXEL Device 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 ZyXEL Device 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 ZyXEL Device 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.
Summary of Contents for 802.11g ADSL 2+ 4-Port Security Gateway HW-D Series
Page 2: ......
Page 10: ...P 662H HW D Series User s Guide 10 Customer Support ...
Page 24: ...P 662H HW D Series User s Guide 24 Table of Contents ...
Page 32: ...P 662H HW D Series User s Guide 32 List of Figures ...
Page 38: ...P 662H HW D Series User s Guide 38 List of Tables ...
Page 64: ...P 662H HW D Series User s Guide 64 Chapter 2 Introducing the Web Configurator ...
Page 84: ...P 662H HW D Series User s Guide 84 Chapter 4 Bandwidth Management Wizard ...
Page 108: ...P 662H HW D Series User s Guide 108 Chapter 5 WAN Setup ...
Page 122: ...P 662H HW D Series User s Guide 122 Chapter 6 LAN Setup ...
Page 156: ...P 662H HW D Series User s Guide 156 Chapter 8 DMZ ...
Page 202: ...P 662H HW D Series User s Guide 202 Chapter 11 Firewall Configuration ...
Page 210: ...P 662H HW D Series User s Guide 210 Chapter 12 Anti Virus Packet Scan ...
Page 214: ...P 662H HW D Series User s Guide 214 Chapter 13 Content Filtering ...
Page 232: ...P 662H HW D Series User s Guide 232 Chapter 14 Content Access Control ...
Page 238: ...P 662H HW D Series User s Guide 238 Chapter 15 Introduction to IPSec ...
Page 273: ...P 662H HW D Series User s Guide Chapter 17 Certificates 273 Figure 144 My Certificate Details ...
Page 292: ...P 662H HW D Series User s Guide 292 Chapter 18 Static Route ...
Page 304: ...P 662H HW D Series User s Guide 304 Chapter 19 Bandwidth Management ...
Page 308: ...P 662H HW D Series User s Guide 308 Chapter 20 Dynamic DNS Setup ...
Page 332: ...P 662H HW D Series User s Guide 332 Chapter 22 Universal Plug and Play UPnP ...
Page 338: ...P 662H HW D Series User s Guide 338 Chapter 23 System ...
Page 344: ...P 662H HW D Series User s Guide 344 Chapter 24 Logs ...
Page 350: ...P 662H HW D Series User s Guide 350 Chapter 25 Tools ...
Page 364: ...P 662H HW D Series User s Guide 364 Chapter 27 Troubleshooting ...
Page 368: ...P 662H HW D Series User s Guide 368 Product Specifications ...
Page 372: ...P 662H HW D Series User s Guide 372 Appendix C Wall mounting Instructions ...
Page 408: ...P 662H HW D Series User s Guide 408 Appendix F Wireless LANs ...
Page 420: ...P 662H HW D Series User s Guide 420 Appendix H Command Interpreter ...
Page 436: ...P 662H HW D Series User s Guide 436 Appendix L NetBIOS Filter Commands ...
Page 462: ...P 662H HW D Series User s Guide 462 Appendix M Internal SPTGEN ...
Page 484: ...P 662H HW D Series User s Guide 484 Appendix P Triangle Route ...