Abstract: Generation of a set of spreading codes starts with determining first and second chaotic pseudo-random noise codes having delta-peak-like autocorrelation functions and a low cross-correlation function.

Abstract: A sealing device including a housing and a closure member having a first end and a second end, at least one of the first and second ends being removably attached to the housing, the housing having means for checking the integrity of the closure member and a first transponder for transmitting information on the status of the sealing device where, the sealing device further includes a second transponder, preferably a passive transponder, associated with at least one of the first and second ends (16, 20) of the closure member, the second transponder comprising a second identity, and a transponder reader associated with the first transponder, preferably an active transponder, the transponder reader being arranged for reading the second identity of the second transponder; the first transponder being configured for receiving the second identity from the transponder reader and for transmitting the second identity.