Fast-software-implemented pseudo-random code generator

A data scrambling method, comprising:

• indexing a first array using a scrambling seed code to retrieve a pointer,
• iteratively:
• indexing a second array using the pointer to retrieve a multi-bit segment of a periodic pseudo-random code from a memory array storing multiple segments of the pseudo-random code, wherein the content of each stored segment of the pseudo-random code is partially redundant to content of at least one other segment stored in the array,
• scrambling a corresponding amount of source data using the pseudo-random code segment, and
• when there is more source data to scramble, advancing the pointer by a regular amount.

A secure communication method, comprising:

• exchanging a seed code between a transmitter and a receiver,
• by the transmitter, scrambling source data using a first pseudo-random code derived from the seed code and transmitting it to the receiver,
• by the receiver, receiving the scrambled data and recovering source data therefrom using a second pseudo-random code derived from the seed code,
• wherein the first and second pseudo-random codes are the same, and
• wherein at least one of the transmitter and the receiver generate the pseudo-random code by a method comprising:
• from the seed code, generating a pointer into a memory array, the array storing previously calculated segments of the pseudo-random code, each stored segment being partially redundant to content of at least one other stored segment;
• and
• iteratively, retrieving a multi-bit code segment from the memory array addressed by the pointer, scrambling a corresponding amount of source data using the retrieval code segment and, unless the iterative process is to conclude, advancing the pointer.

A computer readable medium, storing program instructions that when executed, cause a processing circuit to:

• generate a pointer into an array in response to a seed code, the array storing previously calculated segments of a pseudo-random code, each stored segment being partially redundant to content of at least one other stored segment;
• and
• iteratively:
• retrieve a multi-bit code segment from the memory array addressed by the pointer,
• scramble a corresponding amount of source data, and if another iteration is to occur, advance the pointer by a regular amount.

A method of generating a periodic code, comprising:

• given a seed code, generating a pointer into an array, the array having K entries, each entry storing a previously-generated multi-bit segment of the code having a width M, the segment of each entry starting at a unique position within the periodic code and being partially redundant to content of at least one other stored segment;
• and
• iteratively, until a final iteration is reached:
• retrieving the segment identified by the pointer, and
• advancing the pointer;
• wherein K represents the period of the code.

A method for generating scrambled data using a periodic pseudo-random code, comprising:

• determining a location in a static memory array of previously calculated segments of the pseudo-random code, each segment being partially redundant to content of at least one other segment;
• and
• iteratively:
• retrieving a multi-bit code segment from the location in the static memory array, scrambling a corresponding amount of source data using the retrieved code segment, and if the method is to continue through another iteration, modifying the location by a regular amount.