Abstract: A system and method for transmitting and receiving secret information, a device using the same, and a wireless local communication device. The system for transmitting and receiving secret information includes at least one device to generate a ciphertext using public key information that is received over a location-limited channel; and a wireless local communication device to transmit the public key information to the device over the location-limited channel and to decrypt the ciphertext generated at the device. Thus, the secret information can be securely transmitted and received between devices regardless of reliability of the transmission channel.

Abstract: An apparatus and method are provided for reducing time taken for generating a digital signature and generating the digital signature using a minimum number of operations using at least two secret keys. One secret key among at least two secret keys may be set from a value resulting from hashing a message to be transmitted. A number of times for hashing the secret key is determined, and a value resulting from hashing the determined secret key by the determined hashing number of times is set as the digital signature.

Abstract: Provided are a method and an apparatus for generating and validating a digital signature. The apparatus for generating the digital signature includes: a converter converting a message to be transmitted into a codeword having a set length using a Griesmer code; and a digital signature generator allowing each of bits constituting the codeword to correspond to one of a plurality of secret keys constituting a table and combining the corresponding secret keys to generate the digital signature. The apparatus for validating the digital signature includes: a converter converting a received message into a codeword having a set length using a Griesmer code; and a digital signature validator allowing each of bits constituting the codeword to correspond to one of a plurality of public keys constituting a table and validating whether a value obtained by combining the corresponding public keys is equal to a value obtained by hashing the digital signature.

Abstract: An ownership sharing method and apparatus using a secret key in a home network remote controller are provided. A user who owns a home device generates an ownership authentication key using the secret key shared with the home device through the user's terminal device, and transmits the ownership authentication key to a terminal device of a particular user who wishes to share the ownership. The particular user can use the home device using the shared ownership authentication key, allowing for ownership of a device in home network environments based on a secret key that can be easily shared, obviating complicated calculation procedures that are no needed to share the ownership between an owner of a device and his family or customers, and achieving high security that is guaranteed based on the secret key.

Abstract: A method and system for protecting a broadcast frame are provided. A frame broadcasted through a packet switching network is protected and a wireless LAN system is included. A current frame is authenticated based on a TESLA scheme. The authentication of the broadcast frame can be performed without a time difference.

Abstract: A radio frequency identification (RFID) tag encryption method and system using a broadcast encryption (BE) scheme are provided by encrypting an ID of an RFID tag, storing the encrypted ID in a server and the RFID tag, and storing information relating to a reader authorized to read out the RFID tag in the server so that the reader can read out the RFID tag by decrypting the encrypted ID based on the encrypted ID information read from the RFID tag and the reader information. When readers read out ID data from the RFID tag, a privileged reader can read the data. Thus, it is possible to block unintended information leakage to the readers. In addition, user usability can be enhanced since an attacker cannot perform an access lock on the RFID tag.

Abstract: A communication system including a device, an access point (AP) communicating with the device, and a mobile terminal communicating with the device and the AP, and a method in which the device and the AP share a device key that is a private key used in wireless local area network (WLAN) communication, are provided. A one-directional function operation module is provided in each component constituting the communication system, thereby enabling one-directional function operation. Data to be transmitted and received is applied to one-directional function operation in one-directional function operation module, such that the data can be securely transmitted or received.

Abstract: A method and system for authenticating a home device in a home network, includes generating a home key for authentication of the home device, receiving a secret key corresponding to the home device from the home device, encrypting the home key with the received secret key, and transmitting the encrypted home key to the home device. The home device decodes the encrypted home key using the secret key and then stores the home key. Accordingly, the authentication of the home device is performed without requiring a home server, which would cause an overhead, and the processing of a guest device and a revoked device are performed.

Abstract: An authentication method and system are provided for devices in a home network. The device authentication method includes: storing a secret key list that contains IDs of computationally weak devices without public key operational capabilities, each ID being provided from the respective computationally weak device, and secret keys corresponding to the IDs; receiving session information including a session from a computationally weak device; operating the session information based on the secret key list, and authenticating the computationally weak device; if the computationally weak device is authenticated, generating authentication acknowledgement information about the session information and the authentication of the computationally weak device, and transmitting the information to a general device with public key operational capabilities; and at the general device, carrying out an operation on the received session information and extracting the session.

Abstract: A method and system for authenticating a home network device in a home network. According to the device authentication method, a public key list that includes an ID and public key information corresponding to the ID of home network devices is maintained. When an access of a joining device is received, it is requested to the joining device an ID and information relating to a public key of the joining device. The ID and the public key information are received from the joining device, and the public key list is updated by adding the received ID and public key information. The public key list before updating is transmitted to the joining device. The ID and the public key information of the joining device are transmitted to the home network devices. The joining device is a new device that joins a home network.

Abstract: A method of obtaining C=(c0, . . . , cn-1) of a product of two elements A and B of a finite field GF(2n). The method includes permuting the last d coefficients (an-1, . . . , an-d) of a multiplier A with predetermined variables (sn-1, . . . , sn-d); operating C:C=?(bi+j?A) for (I+j)th coefficient of a multiplicand B to update coefficients of C, where i and j are integers, and A:=(sn-1-j,?0, . . . ,?n-2)?(0,sn-1-j?f1, . . . ,sn-1-j?fn-d,0, . . . ,0) repeatedly for j=0 to (d?1) to update coefficients of A, where ? represents an XOR operation and ? represents an AND operation; and repeatedly performing the permuting and operating by increasing i from 0 to (n-1) by d.

Abstract: A security system using an RSA algorithm that includes a key input section for receiving a secret key and a public key used in one of encryption and decryption of a message, a random coefficient generating section for generating a random coefficient r having a bit of a predetermined size, a first calculation section for dividing the secret key into a first secret key and a second secret key by using the value of r, and performing an exponentiation of RSA algorithm by using the respective secret keys and the public key, and a second calculation section for performing one of the encryption and the decryption by combining results of exponentiation calculated respectively by using the first and the second secret keys.

Abstract: A method and apparatus to square an element A when a defining polynomial of a finite field GF(2n) is expressed as f ? ( x ) = x n + ? i = 1 i ? ? ? x k 1 + 1 , and the element A contained in the finite field is expressed as A?(a0,a1,a2 . . . ,an?1)?GF(2n).

Abstract: Disclosed is a modular multiplication apparatus for high-speed encryption/decryption and electronic signature in a mobile communication environment including smart cards and mobile terminals. The present invention provides an apparatus for performing Montgomery type modular multiplication for calculating A·B·R−1modN (where R=4m+2) in m+2 (where m=n/2) clocks with the multiplier A and the multiplicand B, each having n bits as its inputs, wherein bits of the multiplier are sequentially shifted to generate a shifted bit string and the two least significant bits of the generated bit string are Booth-recorded. The present invention provides a high-speed modular multiplication apparatus with fewer gates and reduced power consumption.

Abstract: There are provided efficient basis conversion matrices Dsd and Dds and a basis conversion method in a finite field GF(2n) using the basis conversion matrices for a case where a defining polynomial is a pentanomial, xn+xk(3)+xk(2)+xk(1)+1, and the exponents n, k(3), k(2), and (k1) satisfy the condition, n−k(3)>k(3)−k(1). In addition, an apparatus for the basis conversion in the finite field GF(2n) is provided. Since a pentanomial having a general form in an arbitrary degree is used as the defining polynomial, basis conversion between a standard representation and a dual representation is efficiently performed. Consequently, a dual basis multiplier can be efficiently implemented.