Disclosed examples decrypt a first block of sequential blocks using a first decryption key generated based on a first hash of a second decryption key and bit stream data, the first decryption key associated with the first block of the sequential blocks to generate a first segment of a band entropy coded bit stream; generate a third decryption key for a second block of the sequential blocks based on a second hash of the first decryption key and data of the first block of the sequential blocks; decrypt the second block of the sequential blocks using the third decryption key associated with the second block of the sequential blocks to generate a second segment of the band entropy coded bit stream; and merge the first and second segments of the band entropy coded bit stream to generate a source data bit stream using a bit mask for demultiplexing.