Abstract: A method for the implementation of modular multiplication according to the Montgomery method, wherein a multiplicand A and a multiplier B are encoded respectively on a and b words of k bits, the most significant words of A and B being non-zero, a modulo N is encoded on m words of k bits, the modulo having (m-m') most significant words with k zero bits, with 0<m'<m. The method includes steps of multiplication in a multiplication circuit having a serial input to receive data elements encoded on at least m' words of k bits, a parallel input to receive encoded words of k bits, and a serial output, wherein, during the performance of the multiplication, a predetermined number p of words is given successively to the parallel input of the multiplication circuit, p being independent of m and greater than or equal to the number a.

Abstract: An electronic document delivery system and method in which a broadcast center periodically sends a "catalog" of available documents to a receiving computer, thereby allowing a user to browse through the available documents without having to access the broadcast center. The documents are transmitted as packets, and the packets are decrypted as soon as they are received, eliminating the need to store both an encrypted and an decrypted version of the documents at the receiving computer. The receiving computer periodically receives information allowing it to decrypt received documents and to encrypt billing information for the receiving computer. The invention is not limited to text-only documents and can receive all types of documents, such as software, images, text, and full-motion video.

Abstract: A simple encryption and decryption device has been developed. The underlying algorithm is a fast block cipher that may be implemented efficiently in hardware or software. The algorithm makes heavy use of data-dependent rotations. The amount of each rotation depends on the data being encrypted and intermediate encryption results. The variables for the algorithm include word size, rounds, and the length of a secret key.

Abstract: A digital voice recording/reproducing apparatus comprises a user identification code memory, provided in a main body, for storing a predetermined user identification code in advance before the apparatus is shipped from a factory, a voice cartridge attaching section for attaching a detachable voice cartridge having a semiconductor memory to the main body, and a user identification code writing section for writing the user identification code stored in the user identification code memory in advance to the semiconductor memory of the voice cartridge attached to the main body.

Abstract: The invention provides a vehicle security device utilizing a rapid encryption method which operates on the basis of a "one-way function" and which requires storage in the vehicle of at most one item of secret coded information in a single piece of equipment, out of any desired number of pieces of equipment involved in vehicle security. In all such pieces of equipment only the one-way function values corresponding to inverse images stored in a key unit need to be present, the reading out of the said one-way function values making unauthorized manufacture of a copied key impossible. Security against interception and storage of information transmitted at the key end in order to produce copied keys is ensured by including an item of random information, transmitted at the vehicle end, in this authentication information.

Abstract: A method for accessing a selected group of data which is stored on a machine readable storage medium, which method includes: assigning a first identifying designation to the storage medium; assigning a second identifying designation to a machine which can read the storage medium; assigning a third identifying designation to the selected group of data; obtaining an access code which is a function of the first, second and third identifying designations; inputting the access code into the machine; and processing the access code in the machine for receiving the third identifying designation.

Abstract: Electronic signature apparatus and method provide an electronic signature that can be created only by a signer, but cannot be used for other than the signature object document to be processed, and that can be verified and authenticated as an image. Since the verified result is an image, such as a print of a seal and a signature, the verifier can easily verify the validity of the image. In addition, since a signature image and a signature object document may separately be processed, combined, and decomposited upon decryption, they can effectively be used for a printed signature.

Abstract: A collection system using a CD ROM computer system wherein the collection items (or more specifically their unlocking keys) are contained in various floppy disks. With the disks inserted into the computer system, the icons of the collection items on the disks appear on the computer monitor. By (double) clicking on the icon, the unlocking key unlocks the corresponding collection item in the CD ROM program into the hard drive and at the same time the unlocking key is rendered inoperative. A generally reverse process can be used to lock the collection item relative to the hard drive and render the unlocking key operative. The user collects the collection items by unlocking, using a number of floppy disks, the locks in his CD ROM program, which contains the corresponding locks for all of the collection items in the set. When the entire set or a predetermined subset thereof has been collected, the CD ROM program allows the user to play an interactive game related to the collection items.

Abstract: The specification discloses a laser alignment head system for taking alignment data with respect to a pair of coupled shafts. Each alignment head includes a laser, a laser sensor for sensing a laser beam, an angle sensor for sensing the rotational orientation of the laser head, a computer and a transmitter for transmitting data from the laser head. The two laser heads are mounted on the two shafts in an opposing facing relationship with the laser beam of one head disposed on the laser sensor of the other head. As the shafts are rotated, the laser beam moves on the laser sensor and the laser sensor generates a position signal corresponding to such movement. Likewise, the angle sensor produces an angle signal corresponding to the rotational angle of the laser head as the shafts are rotated. The computer produces output data corresponding to the position signal and the rotational angle, and such data is transmitted to a receiver.

Abstract: A subscriber terminal includes a digital conditional access module receiving a transport bitstream comprising a plurality of multiplexed conditional access and product packets. Selected ones of the conditional access packets are addressed to respective terminals and include an encrypted new decryption key code, an encrypted authorization bit map and an authorization list range delete code. The conditional access packets are decrypted by the conditional access modules of respective addressed terminals, the decrypted new decryption key code being stored for subsequent use by the conditional access module, the decrypted authorization bit map being used to refresh the authorization bit map memory of the module and the decrypted delete code being used to delete a specified range of authorization codes from the authorization list memory of the module.

Abstract: A method of recovering from a compromise of a root key which is the private key of a first public key-private key pair, the method including the steps of electronically sending out an emergency message indicating that the root key has been compromised and also containing a replacement key and a digital signature which was generated by using the root key; and publishing in an out-of-band channel a value V, wherein V is derived from the emergency message.

Abstract: A method and apparatus for encrypting and decrypting data using a transform which is a function of input data and a basis. After the input data is received, the basis is generated from key values specifying characteristics of a cellular automata space of at least one cell and at least one rule of interaction for the at least one cell. Using the generated basis, the input data is transformed into encrypted or decrypted data.

Abstract: A video signal processor is capable of executing on/off control of a copy inhibiting process and rendering extremely difficult any illegal cancellation of the copy inhibiting process by a third person. This video signal processor includes an obstructor for obstructing proper recording of a video signal; a memory for storing a specific code inputted when enabling the obstructor, and also for storing a disable request code inputted in response to a request for disabling the obstructor; a judge device for judging the relationship between the value of the specific code and the value of the disable request code outputted from the memory; and a decider for deciding an operation to disable the obstructor in accordance with the output of the judge means. The memory has a plurality of registers, and at least one of the bit components of the specific code and the disable request code is stored dispersedly in the plural registers in the memory.

Abstract: A CATV system including a CATV network and apparatus for transmitting over the CATV network information to a multiplicity of subscriber units, each including a CATV decoder and an IC card reader and writer coupled to the CATV decoder, the IC card reader and writer includes two separate IC card receptacles, such that IC cards inserted into the two separate IC card receptacles are separately accessed by the IC card reader and writer.

Abstract: A computer system and method is provided for authenticating the identity of an authorised person. The basic concept is that a permitted user of an identification article such as a credit card will be given a personal identification number with the card and will be instructed not to use the personal identification number in the form in which it has been given but only to use deliberately corrupted versions thereof. The computer system is then set up to detect whether the personal identification number offered for use is a properly corrupted version of the original personal identification number.

Abstract: A system for preventing unauthorized copying of recorded information has a number of independently identifiable storage media holding the information in encrypted form and a number of drives for the storage media, the drives each having a key which decrypts the information on at least one of the storage media. The drives are in communication with a host computer which compares the identities of the storage media with each other and with an authorized list of identities. Should an identity be unauthorized or duplicated, indicating unauthorized copying, the host computer can send a message to the corresponding drive that disables either that drive or the storage medium having that identity. The host computer periodically revises the encryption codes of the control and storage media that are authorized and not duplicated.

Abstract: The geometric measurement of a vehicle is effected by apparatus comprising a casing (1) with an axle (2) protruding from the casing. The axle (2) is mounted for rotation in the casing (1) and engages with its protruding end and is fixed to a support element (3) secured to a wheel of the vehicle to be inspected. The casing (1) contains a camera block (13) for measuring the orientation of the wheel in the vertical plane, a potentiometer (12) for following the angle of the wheel, a device (11) for measuring inclinations in a vertical plane perpendicular to and in a vertical plane parallel to the wheel, connected to an electronic card (10). The camera block (13), the potentiometer (12) and the device (11) connected to an electronic card (10) emit electrical signals representative of indications correlated with the physical parameters to be detected for the geometrical inspection of a vehicle.

Abstract: Apparatus for geometric measurement, particularly for a vehicle with steered wheels or wheels that are only slightly steered or are not steered, of the type comprising two first measuring casings and two second measuring casings from each of which second casings extends a longitudinal arm carrying at its end an angular measuring device. The two first casings (6, 7) are fixed on the steered wheels (2, 3) and the two second casings (8, 10, 12; 9, 11, 13) are secured on the unsteered or only slightly steered wheels (4, 5), so as to avoid any substantial deviation of the arms (10, 11) during geometric measurement of the vehicle. The first casings (6, 7) are each substantially internal to an imaginary geometrical cylinder (C.sub.6 or C.sub.7) with an axis (A.sub.6 or A.sub.7) corresponding to the axis of rotation of the steered wheel (2 or 3) and of a diameter corresponding to the diameter of the rim of the wheel (2, 3).

Abstract: A key escrow technique is disclosed which permits cryptographic limits on wiretapping warrants. Specifically, time limits on wiretaps may be enforced. In addition, the wiretapper is targeted to a specific party or specific pairs of parties communicating in a network.

Abstract: Secure point-to-point communication of information to specific terminals is provided via a shared network. Far in advance of the establishment of an information session with a particular one of a plurality of terminals, a unique session identifier is securely delivered to the terminal by a highly secure entity. Information to be provided to the terminal is subsequently encrypted under the session identifier of that terminal by an insecure connection manager. The encrypted information is inserted into designated locations in a signal multiplex. The signal multiplex is transmitted over a portion of the network serving the terminal that is to receive the information. The terminal is informed of the designated locations of the encrypted information in the signal multiplex and of a transmission frequency at which the signal multiplex is carried on the network portion.