1. A method for encoding steganographic messages comprising: parsing, from a code segment, a sequence of invariants, the invariants corresponding to fixed values in an instruction sequence, each invariant defined by an invariant symbol; selecting a message from a sequence of message symbols from an alphabet; and defining a translation alphabet by mapping each message symbol in the selected message to a successive invariant in the sequence of invariants, the mapping associating each of the invariant symbols to a subset of the message symbols from which the message is composed, each occurrence of an invariant symbol associated with a plurality of message symbols in the subset of symbols.