1
Martin E Hellman, Bailey W Diffie, Ralph C Merkle: Cryptographic apparatus and method. Stanford University, Flehr Hohbach Test, April 29, 1980: US04200770 (891 worldwide citation)

A cryptographic system transmits a computationally secure cryptogram over an insecure communication channel without prearrangement of a cipher key. A secure cipher key is generated by the conversers from transformations of exchanged transformed signals. The conversers each possess a secret signal an ...


2
Martin E Hellman: Software distribution system. Flehr Hohbach Test Albritton & Herbert, April 14, 1987: US04658093 (879 worldwide citation)

Software (programs, videogames, music, movies, etc.) can be authorized for use a given number of times by a base unit after which the base unit (computer, videogame base unit, record player, videorecorder or videodisk player) cannot use that software until the manufacturer sends an authorization for ...


3
Martin E Hellman, Ralph C Merkle: Public key cryptographic apparatus and method. The Board of Trustees of the Leland Stanford Junior University, August 19, 1980: US04218582 (520 worldwide citation)

A cryptographic system transmits a computationally secure cryptogram that is generated from a publicly known transformation of the message sent by the transmitter; the cryptogram is again transformed by the authorized receiver using a secret reciprocal transformation to reproduce the message sent. T ...


4
Martin E Hellman, Stephen C Pohlig: Exponentiation cryptographic apparatus and method. Board of Trustees of the Leland Stanford Junior University, Flehr Hohbach Test Albritton & Herbert, January 3, 1984: US04424414 (324 worldwide citation)

A cryptographic system transmits a computationally secure cryptogram that is generated from a secret transformation of the message sent by the authorized transmitter; the cryptogram is again transformed by the authorized receiver using a secret reciprocal transformation to reproduce the message sent ...


5
Martin E Hellman, Carl E Bach: Method and apparatus for use in public-key data encryption system. Martin E Hellman, December 30, 1986: US04633036 (65 worldwide citation)

In an encryption scheme based on the use of a public key having secret factors p and q, additional requirements on p and q are invoked in order to ensure a high level of security. In particular, it is additionally required that a value p+1 have a large prime factor r and that the value r-1 also have ...


6
Martin E Hellman: Authentication using random challenges. America Online, Standley & Gilcrest, February 16, 1999: US05872917 (59 worldwide citation)

A method is disclosed for authenticating one or both of two parties, for example, a user and a host computer. The first party and second party each know the same password. The first party sends a challenge to the second party. The second party generates and sends to the first party a response based ...


7
Martin E Hellman: Security enhanced tiered subscription broadcast system. Martin E Hellman, Dov Rosenfeld, Inventek, January 4, 2011: US07865917 (10 worldwide citation)

A broadcast system is disclosed that allows a broadcaster to provide multiple levels of subscription services. Subscribers have the option of listening to fewer (or no) commercials if they pay a higher fee, or listening to more commercials if they pay a lower (or no) fee. Commercials can be demograp ...


8
Martin E Hellman: Dropout-resistant media broadcasting system. Martin E Hellman, Dov Rosenfeld, Inventek, September 18, 2012: US08270901

The present invention relates to media broadcast in which memory is used to reduce annoying signal dropouts. A receiver records dropout-free program material and, when a subscriber requests a particular program channel, the radio uses recorded dropout-free program material from the requested channel ...


9
Martin E Hellman: Tiered subscription broadcast system. Martin E Hellman, Dov Rosenfeld, Inventek, January 7, 2014: US08627354

A broadcast system is disclosed that allows a broadcaster to provide multiple levels of subscription services. Subscribers have the option of listening to fewer (or no) commercials if they pay a higher fee, or listening to more commercials if they pay a lower (or no) fee. Commercials can be demograp ...


10
Martin E Hellman: Tiered subscription broadcast system. Martin E Hellman, Dov Rosenfeld, Inventek, September 1, 2015: US09124375

A receiver operating in a broadcast system is disclosed that allows a broadcaster to provide multiple tiers of subscription services. By a receiver that can operating at different tiers, a subscriber has the option of listening to fewer (or no) commercials, e.g., by paying a higher fee, or listening ...