Secure distribution of content

Abstract

Methods and systems are described for secure delivery of a content item from at least a first content distribution network (CDN) 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 e, e, . . . , eand/or for splitting d into k different split-decryption keys d, d, . . . , drespectively, such that D(D( . . . (D(D(E(E( . . . (E(E(X)) . . . ))=D(D( . . . (D(D(X))=X wherein i,k≧1 and i+k>2. The method may comprise: a content source providing said at least one CDNwith at least one an encrypted content item X; 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 CDN, preferably to a first secure module associated with said CDN; generating a partially decrypted content item on the basis of said encrypted content item X, said decryption algorithm D and said first split-key information; and, transmitting said partially decrypted content item to said content receiving entity.