A one-time-pad encryption system where encrypted one-time-pad keys can be distributed to users on physical media or on a computer network from a central server. Each one-time-pad key has a key identification number that facilitates key management. Each encrypted data set includes a header specifying an offset within the one-time-pad key for commencement of decryption so that messages can be decrypted in any order. Before encryption begins, the length of remaining unused key is compared to the length of the data set to be encrypted. Encryption control buttons are added to a word processor and other programs as an addition to the user interface.