Method and apparatus for continuously acknowledged link encrypting

Claim 1

A method of transmitting secure messages between a plurality of locations, comprising the steps of, generating a first sequence of message bits originating in a first location, each bit of which is mixed at said first location with a bit of a second sequence of message bits received from a second location, said mixed first and second bits at said first location establishing a third sequence of bits, said third sequence of bits being transmitted to said second location wherein each bit of said third sequence of bits is mixed with each bit of said second sequence of message bits, whereby said first sequence of message bits is derived at said second location, each bit of said first sequence of message bits being mixed with said second sequence of message bits at said second location, said mixed first and second bits at said second location establishing a fourth sequence of bits, said fourth sequence of bits being transmitted to said first location wherein each bit of said fourth sequence of bits is mixed with each bit of said first sequence of message bits, whereby said second sequence of message bits is derived at said first location, each mixing step occurring on a bit-by-bit basis.

Claim 2

A method of transmitting secure messages between a plurality of locations, comprising the steps of, generating a first sequence of message bits originating in a first location, each bit of which is mixed at said first location with a bit of a second sequence of message bits received from a second location, said mixed first and second bits at said first location establishing a third sequence of bits, said third sequence of bits being transmitted to said second location wherein each bit of said third sequence of bits is mixed with each bit of said second sequence of message bits, whereby said first sequence of message bits is derived at said second location, each bit of said first sequence of message bits being mixed with said second sequence of message bits at said second location, said mixed first and second bits at said second location establishing a fourth sequence of bits, said fourth sequence of bits being transmitted to said first location wherein each bit of said fourth sequence of bits is mixed with each bit of said first sequence of message bits, whereby said second sequence of message bits is derived at said first location, each mixing step occurring on a bit-by-bit basis.

Claim 13

A method for the secure exchange of first and second message bit sequences between first and second stations over first and second communications paths, comprising the steps of: (a) in the first station, generating encrypted bit A by mixing bit A of the first bit sequence with bit B-1 of the second bit sequence received from the second station; (b) transmitting encrypted bit A as part of a third bit sequence from the first station to the second station; (c) receiving encrypted bit A of the third bit sequence at the second station and generating decrypted bit A of the first bit sequence by mixing the third bit sequence therein with bit B-1 of the second bit sequence; (d) in the second station, generating a fourth bit sequence of encrypted bit B by mixing bit B of the second bit sequence with decrypted bit A of the first bit sequence; (e) transmitting encrypted bit B as the fourth bit sequence from the second station to the first station; (f) receiving encrypted bit B of the fourth bit sequence at the first station and generating decrypted bit B of the second bit sequence by mixing the fourth bit sequence therein with bit A of the first bit sequence; (g) incrementing A by one, and, at the first station, mixing bit A of the first bit sequence with decrypted bit B of the second bit sequence; (h) incrementing B by one; and (i) repeating steps (a) through (h) until A equals at least n and B equals at least n.

Claim 14

A method for the secure exchange of first and second message bit sequences between first and second stations over first and second communications paths, comprising the steps of: (a) in the first station, generating encrypted bit A by mixing bit A of the first bit sequence with bit B-1 of the second bit sequence received from the second station; (b) transmitting encrypted bit A as part of a third bit sequence from the first station to the second station; (c) receiving encrypted bit A of the third bit sequence at the second station and generating decrypted bit A of the first bit sequence by mixing the third bit sequence therein with bit B-1 of the second bit sequence; (d) in the second station, generating a fourth bit sequence of encrypted bit B by mixing bit B of the second bit sequence with decrypted bit A of the first bit sequence; (e) transmitting encrypted bit B as the fourth bit sequence from the second station to the first station; (f) receiving encrypted bit B of the fourth bit sequence at the first station and generating decrypted bit B of the second bit sequence by mixing the fourth bit sequence therein with bit A of the first bit sequence; (g) incrementing A by one, and, at the first station, mixing bit A of the first bit sequence with decrypted bit B of the second bit sequence; (h) incrementing B by one; and (i) repeating steps (a) through (h) until A equals at least n and B equals at least n.