Patent attributes
Methods and systems are described for secure delivery of a content item from at least a first content distribution network (CDN1) to at least one content receiving entity using a split-key cryptosystem comprising encryption and decryption algorithms E and D, a cipher algorithm for generating encryption and decryption keys e,d on the basis of secret information S and a split-key algorithm using secret information S for splitting e into i different split-encryption keys e1, e2, . . . , ei and/or for splitting d into k different split-decryption keys d1, d2, . . . , dk respectively, such that Ddk(Ddk-1( . . . (Dd2(Dd1(Eei(Eei-1( . . . (Ee2(Ee1(X)) . . . ))=Ddk(Ddk-1( . . . (Dd2(Dd1(Xe1, e2, . . . , ei))=X wherein i,k≧1 and i+k>2. The method may comprise: a content source providing said at least one CDN1 with at least one an encrypted content item Xe; a key generator associated with said content source comprising said cipher and split-key algorithm generating first split-key information and transmitting said first split-key information to said first CDN1, preferably to a first secure module associated with said CDN1; generating a partially decrypted content item on the basis of said encrypted content item Xe, said decryption algorithm D and said first split-key information; and, transmitting said partially decrypted content item to said content receiving entity.
