Patent ID: 8627081
Filing Date: 2014-01-07
Classification: H04L,H04N

Abstract:
1. A method of transmitting data to a client computer running a client program, the method comprising: (a) transmitting the data to the client program, (b) transmitting software code containing a randomly generated algorithm from a security server to the client program, the algorithm having a result that is a function of a state of client program, the software code further containing a checksum calculation into which a random number and code of the client program and memory image of the client program is input, (c) executing the software code at the client to provide a result of the algorithm, a first calculated checksum, wherein the client program encrypts the random number with a public key of the security server and the encrypted random number is transmitted to the security server with a request for a key and the first calculated checksum, and (d) determining whether the result is indicative of an unmodified client program, wherein the security server decrypts the random number and uses it to encrypt the key, and wherein the security server uses the random number to calculate a second checksum, and the security server then compares the first and second calculated checksums.