Nippon Telegraph and Telephone Corporation

Ntt Research, Inc.

Ntt Innovation Institute, Inc.

Japan Display Inc.

Go Yamamoto

Tetsutaro Kobayashi

Reo Yoshida

Hitoshi Fuji

Tomohide Yamamoto

Masahisa Kawashima

Akira Nagai

Masayuki Abe

Tatsuaki Okamoto

Koutarou Suzuki

Atsushi Fujioka

Eiichiro Fujisaki

Tsunekazu Saito

Moosa Choudhry

Rich Boyer

A digital credential issuing system and method use public storage and encryption to provide a more secure digital credential issuing process because there is no direct interaction between the credential issuer and an entity requesting a new credential. The new credential may be secured, such as by using encryption, so that the newly issued credential may be uploaded to the public storage and then decrypted and used by only the particular entity for which the new credential is intended.

Digital credential issuing system and method

A client apparatus converts second input authentication information having a data content compliant with a second authentication method different from a first authentication method into authentication target information in a data format compliant with the first authentication method and transmits information corresponding to the authentication target information to a communication server apparatus. A server apparatus is capable of carrying out both a first process of providing a first authentication server apparatus that carries out an authentication process compliant with the first authentication method with first information corresponding to the authentication target information and a second process of providing a second authentication server apparatus that carries out an authentication process compliant with the second authentication method with second information corresponding to the authentication target information. The server apparatus transmits authentication result information based on at least one of a result of the authentication performed by the first authentication server apparatus based on the first information and a result of the authentication performed by the second authentication server apparatus based on the second information to the communication server apparatus.

Authentication control system, server apparatus, client apparatus, authentication control method, authentication method, and program

Registered network-based identification corresponding to any of networks is stored in a key device. A terminal devicesends ciphertext and network-based identification to the key device, using a network. The key devicereceives the sent ciphertext and network-based identification and outputs response information corresponding to a decrypted value of the ciphertext when the network-based identification corresponds to the registered network-based identification. The terminal deviceobtains the decrypted value from the response information.

Key device, key cloud system, decryption method, and program

A system and method for private key management in a public key encryption system are disclosed. In one embodiment, the system and method may utilize a 'fake' private key to provide the private key management.

Key management system and method

A security system and method are provided that manage the security of a plurality of internet of things (IoT) devices that are part of an enterprise infrastructure. The security system and method may use unspoofable tags wherein each unspoofable tag may be assigned to a category of IoT devices and each unspoofable tag may have a security policy rule assigned to the unspoofable tag (and thus the category of IoT devices) so that IoT devices that are part of the enterprise infrastructure are secured by the security policy rule.

Security system and method for internet of things infrastructure elements

A computing apparatus outputs &#x3c4;and &#x3c4;corresponding to a ciphertext x, a capability providing apparatus uses &#x3c4;to correctly compute f(&#x3c4;) with a probability greater than a certain probability and sets the result of the computation as z, uses &#x3c4;to correctly compute f(&#x3c4;) with a probability greater than a certain probability and sets the result of the computation as z, the computing apparatus generates a computation result u=f(x)xfrom z, generates a computation result v=f(x)xfrom z, and outputs uvif the computation results u and v satisfy a particular relation, where G and H are groups, f(x) is a function for obtaining an element of the group G for x&#x2208;H, Xand Xare random variables having values in the group G, xis a realization of the random variable X, and xis a realization of the random variable X.

Proxy computing system, computing apparatus, capability providing apparatus, proxy computing method, capability providing method, program, and recording medium

According to an aspect, a display apparatus includes: a display device that displays an image; and a drive circuit that drives the display device. The display device includes a regulator that supplies power based on a predetermined set voltage, a plurality of functional blocks that are operated by the supply of the power from the regulator and are related to operation of the display device, a voltage monitoring circuit that determines whether a level of a power supply voltage of at least one of the functional blocks is high or low based on a predetermined threshold voltage, and a voltage controller that increases the set voltage when the voltage monitoring circuit determines that the power supply voltage of the functional block is lower than the threshold voltage.

Display apparatus

A decoding apparatus performs self-correcting processing with a decoding capability providing apparatus holding a decoding key for decoding first ciphertext which can be decoded by homomorphic operation to obtain a decoding value of the first ciphertext, and performs non-homomorphic operation using a value corresponding to or deriving from the decoding value of the first ciphertext and an addition value to output plaintext.

Decoding apparatus, decoding capability providing apparatus, method thereof and program

Name information which is generated by using a value corresponding to a decryption key and address information of a key cloud device which provides a cloud-key management type decryption service in which the decryption key is used are stored in a storage of a directory service device in a manner to associate the name information with the address information, and a searching unit of the directory service device searches the storage by using the inputted name information to obtain address information corresponding to the inputted name information.

Directory service device, client device, key cloud system, method thereof, and program

A computing apparatus outputs &#x3c4;and &#x3c4;corresponding to a ciphertext x, a capability providing apparatus uses &#x3c4;to correctly compute f(&#x3c4;) with a probability greater than a certain probability and sets the result of the computation as z, uses &#x3c4;to correctly compute f(&#x3c4;) with a probability greater than a certain probability and sets the result of the computation as z, the computing apparatus generates a computation result u=f(x)xfrom z, generates a computation result v=f(x)xfrom z, and outputs uvif the computation results u and v satisfy a particular relation, where G and H are groups, f(x) is a function for obtaining an element of the group G for x&#x3f5;H, Xand Xare random variables having values in the group G, xis a realization of the random variable X, and xis a realization of the random variable X.

The risk of leakage of secret information caused by leakage of a secret key is reduced. A segmented secret-key storage system segments a secret key SK into segments that can be combined at the time of decryption or at the time of generation of a signature and records the secret-key segments sk, . . . , skin segment storage apparatuses. The secret-key segments are changed, periodically or under a predetermined condition, to another set of secret-key segments that satisfies a condition for combination. In the segmented secret-key storage system, the secret key SK is not revealed unless the secret-key segments are stolen from all the segment storage apparatuses in an interval between changes made to the secret-key segments. Accordingly, the risk of leakage can be greatly reduced in comparison with the risk of leakage of the secret key from a single apparatus.

Segmented secret-key storage system, segment storage apparatus, segmented secret-key storage method

A first calculation unit is capable of calculating f(x)xand sets a calculation result of f(x)xto u, and a second calculation unit is capable of calculating f(x)x, and sets a calculation result of f(x)xto v. A final calculation unit outputs (uv)for d=a'a+b&#x2032;b when the calculation result u and the calculation result v satisfy u=v. Here, G and H are groups, f is a function for mapping an element x of the group H to the group G, Xand Xare random variables values of which are in the group G, a realization of the random variable Xis x, a realization of the random variable Xis x, and a, b, a&#x2032;, and b&#x2032; are integers.

Calculation device, calculation method, and program

A computing apparatus outputs &#x3c4;and &#x3c4;corresponding to a ciphertext x, a capability providing apparatus uses &#x3c4;to correctly compute f(&#x3c4;) with a probability greater than a certain probability and sets the result of the computation as z, uses &#x3c4;to correctly compute f(&#x3c4;) with a probability greater than a certain probability and sets the result of the computation as z, the computing apparatus generates a computation result u=f(x)xfrom z, generates a computation result v=f(x)xfrom z, and outputs uvif the computation results u and v satisfy a particular relation, where G and H are groups, f(x) is a function for obtaining an element of the group G for x&#x3b5;H, Xand Xare random variables having values in the group G, xis a realization of the random variable X, and xis a realization of the random variable X.

A private key is held which conforms to an ElGamal encryption system on a semigroup, calculation of an order of an element of the semigroup being computationally difficult, information corresponding to ciphertext conforming to the ElGamal encryption system is input, a private key s is used to decrypt the information corresponding to the ciphertext in conformance to the ElGamal encryption system, and information corresponding to a result of decrypting the ciphertext is obtained and output. Alternatively, whether it is computationally difficult or easy to calculate the order of the element of the semigroup is determined, and the safety of a decryption service providing device is evaluated based on the determination result.

Growing community of inventors

Tokyo, Japan

Go Yamamoto