Nihon Tokushu Noyaku Seizo K.k.

Other

Nec Corporation

Hiroshi Miyauchi

Toshio Goto

Atsumi Kamochi

Toyohiko Kume

Akihiko Yanagi

Shigeki Yagi

Kazue Sako

Katsuhiko Shibuya

Naoya Torii

Yasutsugu Kuroda

Seiichi Domyo

Hiroyuki Ando

Hiroyoshi Tsuchiya

Masashi Yamazaki

Seiko Kanno

Tadao Asami

Ichirou Morita

Hidenori Hayakawa

Naoko Yamaguchi

Ichir{overscore (o)}u M{overscore (o)}rita

A key recovery condition encryption apparatus includes a hashing unit, a first concatenating unit, and a condition information encryption unit. The hashing unit calculates a hash value on the basis of a hash function using a key recovery information text serving as information necessary for performing key recovery. The first concatenating unit concatenates the hash value from the hashing unit to the key recovery condition. The condition information encryption unit encrypts a concatenating result from the first concatenating unit by using a first encryption key. Also is disclosed a key recovery condition decryption apparatus for decrypting the encrypted data from the above encryption apparatus.

Key recovery condition encryption and decryption apparatuses

The present invention has an object to overcome problems of a key recovery system using a conventional KRF system and to achieve efficient operation of the overall key recovery system. A key recovery system of the present invention includes check units,for checking whether a user has a recovery authorization for a common key KS, on the basis of a recovery condition RC specified by a recovery condition index RCI which is added to an encrypted message (encrypted message obtained by encrypting the common key KS with a public key KRCpub) supplied from a terminal (,to,) of the user concerned, and a key recovery control unit,which is provided separately from the check units,and decrypts the encrypted message with a private key KRCpri paired with the public key KRCpub to recover the common key. The check unit,supplies the common key KS recovered in the key recovery control unit,to the user concerned only when the user has the recovery authorization.

Key recovery system and key recovery method

A key recovery information distribution device is provided between a recoverer device and a key recovery device, recovers a data key for the recoverer device, and reduces the load of the recoverer device. Data is encrypted using the data key and stored with key recovery information. The recoverer device which decrypts the encrypted data distributes the key recovery information to key recovery devices through the key recovery information distribution device to recover key information. A recoverer is authenticated directly between the key recovery device and the recoverer device, and then the key information is transmitted to the recoverer device, and the recoverer device recovers the data key.

Key recovery system

An encryption key processing system includes a user terminal system which uses a key and a sub-system for holding information regarding the user terminal system, the sub-system generating predetermined public information, secret information corresponding to the public information and a secret key dependent on an identifier of said user terminal system, sending a secret key to the user terminal system in secret and the user terminal system generating and using a key and necessary information based on a secret key and public information received from the sub-system.

Encryption key processing system to be incorporated into data recovery system or key setting system for generating encryption key

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.

Electronic signature method and apparatus

In apparatus for performing signature verification for an input document on which at least one digital signature is put by at least one signer assigned with a signer's user ID code, an inputting section inputs the signature document. A user ID identifying section identifies the signer's user ID code in the input document to produce an identified user ID code indicative of the signer's user ID code. A user verification key holding unit preliminarily holds user verification keys for respective user ID codes to produce an identified verification key which is one of the user verification keys that corresponds to the identified user ID code. A signature verifying unit verifies the digital signature in the input document by using the identified verification key to produce a signature verification result. A verification result indicator message creating unit creates the verification result indicator message indicative of the signature verification result. An apparatus's signature key holding section holds an apparatus's signature key assigned to said apparatus. A signing section signs at least the verification result indicator message by using the apparatus's signature key to produce a signed document. An outputting section outputs the signed document as an output document.

Signature verification apparatus capable of obtaining information

Herbicidal benzo-fused cyclic compounds of the formula ##STR1## wherein Q is ##STR2## Y is O or S, W is ##STR3## T is O, S, --NH-- or ##STR4## and R.sup.4 may represent, together with T, chlorine,

Benzo-fused cyclic compounds

Herbicidal compounds of the formula ##STR1## in which X denotes an oxygen atom or sulfur atom,

Heterocyclic compounds

Herbicidal 1-phenylpyrroles of the formula ##STR1## wherein each R.sup.1 represents methyl or together form a tetramethylene group,

1-phenylpyrroles

Herbicidally active pyrroles of the formula ##STR1## wherein R.sup.1 represents C.sub.1-4 alkyl, or one R.sup.1 together with the other R.sup.1 forms tetramethylene or butenylene,

Herbicidal novel benzothiazolonyl pyrroles

Herbicidal benzothiazolones of the formula ##STR1## wherein X represents hydrogen or halogen, R.sup.1 represents hydrogen, alkyl, various organic radicals, ##STR2## in which R.sub.2, R.sup.4, R.sup.5 and R.sup.6 each is hydrogen or an organic radical, and R.sup.3 is alkyl, cycloalkyl or optionally halo-substituted phenyl.

Benzothiazolone

Herbicidal 2,5-dihydropyrroles of the formula ##STR1## wherein A represents hydroxy, halogen, an alkylcarbonyloxy group having alkyl with 1 to 4 carbon atoms optionally substituted by halogen, or an alkylsulfonyloxy group having 1 to 4 carbon atoms optionally substituted by halogen,

Herbicidally active 2,5-dihydropyrroles

Herbicidally active novel 2,5-dihydropyrroles of the formula ##STR1## wherein R.sup.1 represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, R.sup.2 and R.sup.3 each represent an alkyl group having 1 to 4 carbon atoms or a haloalkyl group having 1 to 4 carbon atoms or together may form a C.sub.2 -C.sub.6 alkylene group which may be substituted by halogen, and R represents a hydroxy group, a mercapto group, a halogen atom, an amino group or a group of the formula --O--W in which W represents an alkylcarbonyl, a halogenoalkylcarbonyl, an alkoxycarbonyl or a halogenoalkoxycarbonyl group each having 1 to 4 carbon atoms in the alkyl group, an alkylsulfonyl or a halogenoalkylsulfonyl group each having 1 to 4 carbon atoms in the alkyl group or a di-C.sub.1 -C.sub.4 -alkylamino sulfonyl group.

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Tokyo, Japan

Hiroshi Miyauchi