Patent ID: 7865917

Claim:
A receiver in a tiered broadcast system comprising: a digital demodulator; a cryptoprocessor; and a receiver controller; such that: said digital demodulator creates a bitstream; said receiver controller divides said bitstream into at least two substreams; at least one of said substreams is plaintext; at least one of said substreams is ciphertext; at least one of the ciphertext substreams is decrypted by said cryptoprocessor; if said receiver is assigned to a first tier and tuned to a program channel for a time period greater than ten minutes, advertising comprises a first time fraction of said receiver's output signal; if said receiver is assigned to a second tier and tuned to said program channel for said time period, advertising comprises a second time fraction of said receiver's output signal; and the ratio of said first time fraction to said second time fraction is less than 0.95 or greater than 1.05.