Abstract: An improved Internet File Safety Information Center (IFSIC) is disclosed. The improved IFSIC allows an Internet user to look up the authenticity and safety information about a file or group of files by computing a hash value from the file or group of files and sending the hash value to a central server on the Internet to retrieve such information. A user identifier and other information can be sent to the central server along with the hash value. The improved IFSIC can be supported by targeted advertising, can provide file update information, can provide a better filter for files attached to email messages, and can be used to ensure the integrity of operating systems and installed programs.

Abstract: A public-key based secure messaging system with automatic receiver enrollment is disclosed. A sender in the system first determines whether a receiver has a public key. If the receiver has a public key, the messages will be sent to the receiver using a standard public-key based encryption. If the receiver does not have a public key, the first message will be sent to the receiver using a delivery method that does not require the receiver to have a pair of public and private keys prior to sending the message. However, when the receiver accesses the first message, a pair of public and private keys will be automatically generated at the receiver and the public key will be made available for encrypting subsequent messages sent to the receiver.

Abstract: A public-key based secure messaging system with automatic receiver enrollment is disclosed. A sender in the system first determines whether a receiver has a public key. If the receiver has a public key, the messages will be sent to the receiver using a standard public-key based encryption. If the receiver does not have a public key, the first message will be sent to the receiver using a delivery method that does not require the receiver to have a pair of public and private keys prior to sending the message. However, when the receiver accesses the first message, a pair of public and private keys will be automatically generated at the receiver and the public key will be made available for encrypting subsequent messages sent to the receiver.