The presently claimed invention relates generally to digital watermarking and steganographic encoding. One claim recites a method of encoding a watermark in a digital signal. The method includes generating varying key bits; and encoding the varying watermark key bits in the digital signal as a watermark with reference to at least characteristics of the digital signal. The “digital signal” may represent audio, video or imagery. Another claim recites a system for encoding a watermark in a digital signal. The system includes a processor: i) to map pseudo-random key and processing state information to effect an encode/decode map; and ii) to encode a watermark in a digital signal using the encode/decode map and characteristics of the digital signal. Of course other combinations are provided and claimed as well.