Patent ID: 7337332

Claim:
A method for transferring electronic content including multiple portions, comprising: providing electronic content to a first user via a first user's smart card enabled device; providing the first user with a first key packet useful by said first user's smart card enabled device for decrypting said electronic content, said first key packet comprising a first main decryption key and a plurality of dependent decryption keys encrypted by said first main key, each of said plurality of dependent decryption keys being useful for decrypting at least one of said multiple portions of said electronic content, said first key packet being operative to enable creation of a second key packet, at said first user's smart card enabled device, comprising a second main decryption key and said plurality of dependent decryption keys, at least some of which are encrypted by said second main key; and transferring of said electronic content and said second key packet from the first user to a second user.