Abstract:
PURPOSE: A serial-parallel multiplier finding out the multiplication of two elements on a finite field is provided to quickly find out the multiplication of two elements on finite field by performing the modular subtraction for each operation result again after respectively multiplying the divided two multipliers to a multiplicand. CONSTITUTION: A multiplexer(11) alternatively outputs the first and the second multiplier data depending on a selection signal by receiving the multiplier data in parallel. A half multiplier(12) outputs the first operation value by multiplying the first multiplier to the multiplicand data and performing the modular operation, and outputs the second operation value by multiplying the second multiplier to the multiplicand data and performing the modular operation. A storage(13) stores the first operation value at the first cycle and outputs the stored value at the second cycle depending on a clock doubled to the selection signal. A modular subtracter(14) performs the modular subtraction for subtracting the received first operation value from the second operation value.
Abstract:
Provided are a device for privacy protection document authentication information using various privacy protection electronic signatures and multidimensional codes and a method for authenticating a privacy protection document using the same. The provided device comprises: an electronic signature information generation unit to generate privacy protection electronic signature information about document content; a multidimensional code generation unit to generate a multidimensional code corresponding to the generated privacy protection electronic signature information; and a multidimensional code output unit to output the generated multidimensional code to a document. According to the device of the present invention, a privacy protection electronic signature value generated by a personalized smart device can be output to a physical document in the form of a multidimensional code to authenticate the document.
Abstract:
Provided are an apparatus and a method for anonymity-based authentication and key agreement which are capable of providing transmission message binding properties, which ensure that the messages received via a plurality of rounds by participants who desire key agreement as well as anonymity have been sent by the same counterpart participants. The provided apparatus comprises: a signature verification unit which receives a plurality of messages, each carrying a signature generated based on link information of a sender, and verifies the signature of each of the messages; and a binding checking unit which determines whether the messages have been sent by an identical sender, if it is determined by the signature verification unit that the signature is valid, based on the link information of the signature.
Abstract:
PURPOSE: A search available password system at multilateral environment capable of the index verification and tracking and a method thereof are provided to verify the index which is produced by each user, in the data based in which a plurality of user uses at the same time, and are provided to track the user who produced the index. CONSTITUTION: A key distribution center (200) distributes a personal secret key to a user (S102). The key distribution center tracks the information about a user who produced the index (S112). A user terminal device (204) produces the index for searching the database by using the personal secret key (S104). A database (DB) server (202) verifies the index which is produced in the user terminal. The DB server searches and provides the data which corresponds to the verified index (S110). [Reference numerals] (200) Key distribution center; (202) Database (DB) server; (204) User terminal device; (AA) System parameter generation; (BB) Public key distribution; (S104) Index generation; (S106) Index verification; (S108) Trap door generation; (S110) Searching; (S112) Tracing
Abstract:
PURPOSE: A lightweight group signature system with short signatures and a method thereof are provided to improve operation efficiency in signature generation, signature verification, and revocation on smart terminals, while providing security characteristics at a similar level with group signature mechanisms which provide controllable linkability. CONSTITUTION: A key issuing unit(110) initially generates a group public key as a trusted subject and generates a master issuing key(mik), a master opening key(mok), and a master linking key(mlk) corresponding thereto. The key issuing unit performs an interactive protocol, when receiving a join request from a new user device(140), and issues a signature key to the user device. A key revocation identifying unit(120) identifies whether revocation is performed using the updated revocation list and the master opening key when the revocation identification request is received from the signature verifying unit(150) and then, returns the identified results to the signature verifying unit. The key revocation identifying unit uses the master opening key to output the verification information for identifying a signer when a valid signature is given. A signer identification proof evaluating unit(160) evaluates the validity of the signer identification proof generated from a signature control unit(100). [Reference numerals] (100) Control unit; (110) Key issuing unit; (120) Key revocation identifying unit; (130) Signature connecting unit; (140) User device; (150) Signature verifying unit; (160) Signer identification proof evaluating unit; (AA) Generating a group public key; (BB) Master issuing key; (CC) Master identifying key; (DD) Master connecting key; (EE) Confirming signature connection information; (FF) Requesting confirmation of signature connection; (GG) Confirming key revocation; (HH) Requesting confirmation of key revocation; (II) Requesting identification of a signer; (JJ) Issuing a signature key; (KK) Generating a signature; (LL) Generating signer identification proof; (MM) Confirming signer identification proof;