Secure communication via the internet

#The current application claims priority from European Patent Application Number 02076498.1, which was filed on Apr. 16, 2002, the contents of which are incorporated herein by reference.

#The invention relates to secure electronic communication via a communication system, in particular the Internet, using public key encryption.

#Electronic communication has spread widely with the success of Internet and is spreading even further with the arrival of all kinds of wireless communication, for instance using PDAs (Personal Digital Assistants) and mobile phones. Electronic communication can take many forms, such as email, file transport, accessing web sites, etc. Normally, electronic communication is unprotected in the sense that the electronic content can be accessed by many people that have access to the computers involved in the distribution of the electronic content. As an example, sending an email usually involves the sending and receiving computer, access computers that provide both station access to the network, and several routing computers involved in routing the email through the Internet. Even one route may involve a dozen routers, where for each communication different routers may be chosen. Consequently, tens of thousands of operators of all those computers can access electronically exchanged content. Although the operators may be bound by contract or law not to disclose such content, it can never be ruled out that somebody may not be able to resist the temptation. A serious threat to security is also that malicious people may break into (“hack”) one or more of these computers and in that way get access to the electronic content.

#In the drawings:

#FIG. 1 shows an architecture of the system according to the invention;

#FIG. 2 shows a flow diagram of operations in the sending client;

#FIG. 1 shows an architecture of the system according to the invention. The system includes at least one sending station and one receiving station that can communicate via a communication system. The communication system is preferably, but is not limited to a wide area network. The figure shows a typical architecture where the communication infrastructure is based on Internet. The backbone of Internet is indicated by number 100 and is usually formed by routers and wide area links connecting the routers. Two stations 110 and 120 are shown. In the example, the stations can act both as a sending station and as a receiving station as is usually the case for Internet. The stations 110 and 120 gain access to the Internet 100 via respective access providers 130 and 140. Station 120 is a mobile terminal (e.g. mobile phone or PDA) that communicates with its access provider 140 at least partly via a wireless telecommunications network 150. Station 110 is a conventional stationary terminal, such as a personal computer, that communicates to its access provider 130 via a conventional access network 160, such as a telephone line and telecommunication switches or a cable network (and fixed telecommunication lines). According to the invention, a centralized server 170 plays a role in secure communication between the stations 110 and 120. In short, the server 170 plays the role of:

#key intermediary controlling availability of public keys for the involved devices and acting as a key intermediary between the sender and receiver, particularly when one of the parties has not yet obtained the necessary keys;

#communication intermediary, where the communication between the sender and receiver takes place via the server. The communication between the sender and server is secured using the keys of the sender/server, where appropriate. The communication between the server and receiver is managed by the keys of the server/receiver where appropriate.