US Patent 7349886 Securely relaying content using key chains

A system, apparatus, and method are directed towards generating chains of encrypted decryption keys for content in a highly distributed environment. In one embodiment, the key chain may be provided within an Entitlement Control Message (ECM). An access key that enables decryption of a current link within the chain of decryption keys may be provided to a downstream recipient using an out-of-band mechanism. Alternatively, the access key may be provided through an in-band mechanism, such as through the use of Entitlement Management Message (EMM), or the like. In one embodiment, the access key within the EMM may be further encrypted by another encryption key that may be unique to the downstream recipient.