Electronics and Telecommunications Research Institute

Do Won Hong

Hyun Sook Cho

Ku Young Chang

Young Soo Kim

Joo Young Lee

Sang Su Lee

Youn Hee Gil

Keon Woo Kim

Sung Kyong Un

Woo Yong Choi

Su Hyung Jo

Kyo Il Chung

Nam-Su Jho

Taek Young Youn

Yong Je Choi

Hang Rok Lee

Ik Re Jeong

Ju Sung Kang

Mun Kyu Lee

A tag decides a response based on a plurality of queries received from a reader, determines whether to transmit the response, transmits the response to the reader according to the results of the determination, and transmits a message authentication code including communication content to the reader. The reader calculates a consumed time period which is the time difference between a transmission time at which the queries are transmitted and a reception time at which the response is received, calculates an average consumed time period of the consumed time period, and measures a distance to the tag based on the average consumed time period. Accordingly, it is possible to check an attacker's intervention with a high probability, thereby improving distance measurement performance. Also, the tag may efficiently perform computing and communication.

Method of measuring distance bound using radio frequency identification (RFID) and system thereof

A multi-user searchable encryption system includes a key generation center to issue a private secret key to a user and trace information regarding a user who has generated an index, and a user terminal device to generate an index for searching for a database using the private secret key. The multi-user searchable encryption system includes a database (DB) server that verifies the index generated by the user terminal device and searches for corresponding data to the verified index.

Multi-user searchable encryption system and method with index validation and tracing

Proposed is a data visualizing apparatus for visualizing data as effectual information using a correlation between forensic data collected from various sources. The proposed data visualizing apparatus may visualize, as effectual information, single-source single-data, single-source multi-data, and multi-source multi-data.

Apparatus and method for visualizing data

An order-preserving encryption apparatus includes an initializer for setting a total space of a ciphertext with respect to a total space of a plaintext by considering security of the ciphertext, and setting a secret key for encryption and a pseudo-random number generator for generation of a pivot. Further, the order-preserving encryption apparatus includes a pivot generator for applying the secret key to the established pseudo-random number generator to generate a pivot for the plaintext to be encrypted. Further, the order-preserving encryption apparatus includes a ciphertext generator for generating information about size of a bit constituting the ciphertext by comparing the generated pivot and the plaintext; and a plaintext adjusting unit for adjusting a magnitude of the total plaintext space and a magnitude of the plaintext according to the ciphertext.

Order-preserving encryption and decryption apparatus and method thereof

Provided is a forensic index method by distributed processing, including: generating data to be divided by dividing data to be indexed according to predetermined division setting for distributed processing; allocating the generated data to be divided to a plurality of data processing units according to the predetermined division setting, extracting an index by filtering the allocated data to be divided in the plurality of data processing units, and generating divided index data including the extracted index; and generating an index database by merging the generated divided index data.

Forensic index method and apparatus by distributed processing

A system and method for data analysis and digital forensics is provided. The system for data analysis and digital forensics may include: an online data forensic server for collecting and analyzing usage history information from an object device, which is subject to data collection, downloading and collecting data on the Internet based on the usage history information, requesting issuance of a timestamp token for the collected data, and receiving the issued timestamp token; a timestamp token issuing server for issuing the timestamp token for the collected data in response to the request for issuance of the timestamp token and proving the issued timestamp token to the online data forensic server; and a storage device for storing the collected data.

Method for data analysis and digital forensics and system using the same

A ring authentication method for a concurrency environment, the method capable of providing unforgeability, sender anonymity, and deniability in the concurrency environment, in which, when a receiver receiving a message requests a sender of the message to certify the message, the sender requested to certify the message sends a message certification value certifying that the sender is one of a plurality of users {P, . . . , P} and authenticates the message m to the receiver, and the receiver verifies the sent message certification value and authenticates that the message is sent from the one of the plurality of users {P, . . . , P}.

Ring authentication method for concurrency environment

Provided are a key establishment method and system using commutative linear functions. In the method, a server defines a set of linear functions that use elements of a first finite field as coefficients and satisfy a commutative rule, selects a first linear function from the set, and selects a predetermined element from a second finite field. Next, the server selects a second linear function corresponding to each of nodes from the set, generates a predetermined combination function based on the first and second linear functions, generates a value of the second linear function using the selected element as a factor, and transmits the combination function and the value of the second linear function to a corresponding node. Each node receives the value of the second linear function from a server, exchanges the received values with the other nodes, computes a value using the exchanged value as a factor of the combination function, and establishes the computed value as a shared key between the nodes. Therefore, each node can perform key establishment with a small amount of computation and low memory consumption, while guaranteeing end-to-end security.

Key establishment method and system using commutative linear function

An apparatus and method for hybrid multiplication in GF(2) by which trade-off between the area and the operation speed of an apparatus for a hybrid multiplier in finite field GF(2) can be achieved are provided. The apparatus for hybrid multiplication includes: a matrix Z generation unit generating [m&#xd7;k] matrix Z for performing a partial multiplication of a(x) and b(x), by dividing b(x) by k bits (k&#x2266;&#x250c;m/2&#x2510;), when multiplication of m-bit multiplier a(x) and m-bit multiplicand b(x) is performed from [(m+k&#x2212;1)&#xd7;k] coefficient matrix of a(x) in GF(2); a partial multiplication unit performing the partial multiplication &#x250c;m/k&#x2510;k&#x2212;1 times in units of rows of the matrix Z to calculate an (&#x250c;m/k&#x2510;k&#x2212;1)-th partial multiplication value and a final result value of the multiplication; and a reduction unit receiving the (&#x250c;m/k&#x2510;k&#x2212;1)-th partial multiplication value fed back from the partial multiplication unit and performing reduction of the value in order to obtain a partial multiplication value next to the (&#x250c;m/k&#x2510;k&#x2212;1)-th partial multiplication value.

[object Object]

A method and apparatus for generating a keystream are provided. The method includes: (a) receiving a bitstream comprised of at least 4 bits; (b) selecting at least two bits from the received bitstream; (c) generating an operation value by performing a predetermined bitwise operation on the bits selected in (b); and (d) determining whether to discard the received bitstream or to output the rest of the received bitstream not selected in (b) according to the operation value. The method and apparatus for generating a keystream are expected to be suitable for a ubiquitous computing and network environment and to provide high security or high efficiency.

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Daejeon, South Korea

Do Won Hong