Patent ID: 7792289

Claim:
A communications system comprising: a first computer having stored therein a function M and a first set of keys, each key within said first set of keys defining a series of values, said first computer configured to: a) receive a mail-destination and a sequence of original values O j (1≦j≦N, N being the length of the sequence of original values); b) based upon said mail-destination, establish a first key from the first set of keys being a sequence of values established using a function relating to prior values of the sequence; c) using the function M and the first key, transform the sequence of original values O j to a sequence of transformed values E j , and, d) communicate the sequence of transformed values E j and a source identifier to a remote computer; a second computer having stored therein a function M′ and a second set of keys, each key within said second set of keys defining a series of values, said second computer configured to: a) receive the sequence of transformed values E j and the source identifier; b) based upon said source identifier, select one of said keys from the second set of keys; c) using the function M′ and the selected key from the second set of keys, reconstruct the original sequence of values O j from the sequence of transformed values E j ; d) select one of said keys from the second set of keys; e) using the function M″ and the selected key from the second set of keys, transform the sequence of original values O j to a second sequence of transformed values E′ j .