Abstract: An ultrasonic driving apparatus consists mainly of a digital oscillatory circuit, an amplifier, a detection circuit, a phase difference detection circuit, a register, a data transfer circuit, and a switching circuit. The digital oscillatory circuit is used to drive an ultrasonic transducer at the resonance frequency of the ultrasonic transducer. The amplifier amplifies a driving signal output from the digital oscillatory circuit. The detection circuit detects the phase &thgr;v of an applied voltage and the phase &thgr;i of an induced current from the driving signal applied to the ultrasonic transducer via the amplifier. The phase difference detection circuit detects a difference between the phases &thgr;v and &thgr;i. The register holds digital frequency data with which a frequency at which the digital oscillatory circuit is oscillated is determined, and changes the digital frequency data. The data transfer circuit transfers the digital frequency data to the register.

Abstract: In an electrosurgery apparatus for treating a living tissue, while the living tissue is being treated, a variation in state of energy supplied from a cautery power supply to a monopolar treatment device is detected on the basis of detection data obtained from a current sensor and a voltage sensor. Based on the detected variation, living body information on the living tissue to be treated is obtained.

Abstract: In a key distribution system comprising a first subsystem (11), a second subsystem (12), and a public file (13), the first subsystem transmits distribution information (ID.sub.A, Y.sub.A) to the second subsystem via a communication channel (16). The first subsystem (11) comprises a reading unit (22) for accessing the public file by reception identification information (ID.sub.B) inputted from an input unit (21) to read reception public information (X.sub.B). A first cipher key generator (28) generates a first cipher key (K.sub.A) by applying a first predetermined transformation on the reception public information and the reception identification information on the basis of first and second constants (n, t), and a random number (r). A distribution code generator (29) generates a key distribution code (Y.sub.A) by applying a second predetermined transformation on transmission public information (X.sub.A) and a third constant (.alpha.) on the basis of the first constant, first secret information (r.sub.

Abstract: A cipher-key distribution system used in a one-way communication from a first party to a second party. The cipher-key distribution system is composed of a first subsystem, a second subsystem, and a common file which stores information publically accessible by the first and second subsystems. The first subsystem generates a cipher-key based on a constant, receiving party identifying information, a random number, and public information from the common file. The first subsystem also generates a key distributing code based on a constant, a random number and a first secret information and transfers the key distributing code to a second subsystem. The second subsystem receives the key distributing code and information for identifying the first party and generates a second cipher-key identical to the cipher-key generated by the first subsystem. The second cipher-key is created from the information for identifying the first party, a second secret information, and the key distributing code.

Abstract: A method and apparatus for matching fingerprints is provided in which the collation rate is improved by using both characteristic and non-characteristic minutia for the collation process. An image processing unit used in the apparatus cannot determine whether the collation minutia searched are characteristic or non-characteristic since an IC card holds a list of collation minutia records, thus offering improved security. Further, random numbers may be utilized for accessing the collation minutia record list for further improved security.