Abstract: A geo-location provider station signs geo-location data and a previous signature provided by a mobile device, returning a new signature to the mobile device. The mobile device uses the new signature when requesting a signature from another geo-location provider station. The mobile device stores the geo-location data and the signatures provided by geo-location provider stations. The stored geo-location data may be verified upon request by using the stored signature data.

Abstract: In an example, a stack protection engine is disclosed for preventing or ameliorating stack corruption attacks. The stack protection engine may operate transparently to user-space processes. After a call to a subroutine from a parent routine, the stack protection engine encodes the return address on the stack, such as with an exclusive or cipher and a key selected from a key array. After the subroutine returns control to the main routine, the stack protection engine decodes the address, and returns control. If a stack corruption attack occurs, the malicious return address is not properly encoded, so that when decoding occurs, the program may simply crash rather than returning control to the malicious code.

Abstract: In an example, a stack protection engine is disclosed for preventing or ameliorating stack corruption attacks. The stack protection engine may operate transparently to user-space processes. After a call to a subroutine from a parent routine, the stack protection engine encodes the return address on the stack, such as with an exclusive or cipher and a key selected from a key array. After the subroutine returns control to the main routine, the stack protection engine decodes the address, and returns control. If a stack corruption attack occurs, the malicious return address is not properly encoded, so that when decoding occurs, the program may simply crash rather than returning control to the malicious code.

Abstract: A geo-location provider station signs geo-location data and a previous signature provided by a mobile device, returning a new signature to the mobile device. The mobile device uses the new signature when requesting a signature from another geo-location provider station. The mobile device stores the geo-location data and the signatures provided by geo-location provider stations. The stored geo-location data may be verified upon request by using the stored signature data.

Abstract: A request for secure data sent from a client computer 2 to a webtsite server computer 4 is redirected to a proxy computer 6. A secure connection is established with the proxy computer 6 using a protocol such as HTTP and Certificate Exchange. The proxy computer 6 then establishes its own secure connection with the website server 4. The data requested is passed in encrypted form from the website server computer 4 to the proxy computer 6. The proxy computer 6 decrypts this data and then scans it for illegal content, such as computer viruses, worms, Trojans, banned computer files, banned words, banned combinations of words or banned images and the like. Providing no illegal content is found, the data is encrypted again for transfer over the secure link between the proxy computer 6 and the client computer 2. The proxy computer 6 may conveniently be the firewall computer within a local area network.

Abstract: A request for secure data sent from a client computer 2 to a webtsite server computer 4 is redirected to a proxy computer 6. A secure connection is established with the proxy computer 6 using a protocol such as HTTPS and Certificate Exchange. The proxy computer 6 then establishes its own secure connection with the website server 4. The data requested is passed in encrypted form from the website server computer 4 to the proxy computer 6. The proxy computer 6 decrypts this data and then scans it for illegal content, such as computer viruses, worms, Trojans, banned computer files, banned words, banned combinations of words or banned images and the like. Providing no illegal content is found, the data is encrypted again for transfer over the secure link between the proxy computer 6 and the client computer 2. The proxy computer 6 may conveniently be the firewall computer within a local area network.