Class of binary cipher sequences with best possible autocorrelation function

A new class of binary sequences called here `m-like cipher sequences¿¿ are introduced which have rather interesting properties for use as cipher sequences. These are derived by interleaving the so-called `elementary m-sequences¿¿ along with some null sequences in a particular order. The resulting composite sequences are not m-sequences, but require deciphering and storage of a much larger number of bits for their complete prediction from the observed cipher text than that needed for predicting m-sequences of the same length. At the same time, the method of construction of these sequences ensures that their autocorrelation function is identical to that of an m-sequence of the same length.