3Com 2928 User Guide - Page 422

VPN A virtual private network (VPN) is a private data communication network built on the public communication infrastructure. A VPN can leverage network layer security protocols (for instance, IPSec) in conjunction with PKI-based encryption and digital signature technologies to achieve confidentiality. Secure E-mail E-mails require confidentiality, integrity, authentication, and non-repudiation. PKI can address these needs. The secure E-mail protocol that is currently developing rapidly is Secure/Multipurpose Internet Mail Extensions (S/MIME), which is based on PKI and allows for transfer of encrypted mails with signature. Web security For Web security, two peers can establish a Secure Sockets Layer (SSL) connection first for transparent and secure communications at the application layer. With PKI, SSL enables encrypted communications between a browser and a server. Both the communication parties can verify the identity of each other through digital certificates. Operation of PKI In a PKI-enabled network, an entity can request a local certificate from the CA and the device can check the validity of certificate. The following describes how it works: 1) An entity submits a certificate request to the CA. 2) The RA verifies the identity of the entity and then sends the identity information and the public key with a digital signature to the CA. 3) The CA verifies the digital signature, approves the application, and issues a certificate. 4) The RA receives the certificate from the CA, sends it to the LDAP server to provide directory navigation service, and notifies the entity that the certificate is successfully issued. 5) The entity retrieves the certificate. With the certificate, the entity can communicate with other entities safely through encryption and digital signature. 6) The entity makes a request to the CA when it needs to revoke its certificate, while the CA approves the request, updates the CRLs and publishes the CRLs on the LDAP server. Configuring PKI Configuration Task List There are two PKI certificate request modes: z Manual: In manual mode, you need to retrieve a CA certificate, generate a local RSA key pair, and submit a local certificate request for an entity. z Auto: In auto mode, an entity automatically requests a certificate through the Simple Certification Enrollment Protocol (SCEP) when it has no local certificate or the present certificate is about to expire. You can specify the PKI certificate request mode for a PKI domain. Different PKI certificate request modes require different configurations: Requesting a certificate manually Perform the tasks in Table 1-1 to request a certificate manually. 1-3