A process for the secure transmission of data is presented that has to a certain degree the advantages of the one-time pad (OTP) cipher, that is, simplicity, speed, and information-theoretically security, but overcomes its fundamental weakness, the necessity of securely exchanging a key that is as long as the message. For each transmission, a dedicated one-time pad is generated for encrypting and decrypting the plaintext message. This one-time pad is built from a randomly chosen set of basic keys taken from a public library. Because the basic keys can be chosen and used multiple times, the method is called multiple-time pad (MTP) cipher. The information on the choice of basic keys is encoded in a short keyword that is transmitted by secure means. The process is made secure against known-plaintext attack by additional design elements. The process is particularly useful for high-speed transmission of mass data and video or audio streaming.