Abstract: In one embodiment, an authentication protocol used in a network security service is performed over non-secure connection, such as HTTP. A router subscribing to the service may send a service request for information about a URL to a server computer providing the service. The service request may be included in a first data set posted by the router to the server computer. The first data set may be described by an HTML form and include an encrypted device authenticator used by the server computer to validate the router. The first data set may further include a server authentication code. In responding to the service request, the server computer returns the server authentication code to the router along with information about the URL. The response may be in a second data set, such as an XML document sent by the server computer to the router over an HTTP connection.

Abstract: Malicious code patterns of an antivirus may be updated using public DNS (domain name system) servers. An update to the malicious code patterns may be generated and divided into several portions for inclusion in DNS records. The DNS records may be published for caching in public DNS servers. An update client in a client computer may send out DNS queries to receive contents of the DNS records, which include the portions of the update. The update client may combine the portions to update the malicious code patterns in the client computer.

Abstract: In one embodiment, an authentication protocol used in a network security service is performed over non-secure connection, such as HTTP. A router subscribing to the service may send a service request for information about a URL to a server computer providing the service. The service request may be included in a first data set posted by the router to the server computer. The first data set may be described by an HTML form and include an encrypted device authenticator used by the server computer to validate the router. The first data set may further include a server authentication code. In responding to the service request, the server computer returns the server authentication code to the router along with information about the URL. The response may be in a second data set, such as an XML document sent by the server computer to the router over an HTTP connection.

Abstract: Methods and apparatus for rating Uniform Resource Locators (URLs) are disclosed. The method includes determining a request size pertaining to a length of the URL to be rated and for generating a rating request message containing the URL. The rating request message is a DNS (domain name system) message if the request size is less than or equal to a predefined size limitation, and the rating request message is a HTTP (hypertext transfer protocol) message if the request size is greater than the predefined size limitation.