Abstract: A radio frequency identification (RFID) tag authentication apparatus and method for accomplishing quick authentication and solving privacy problems using a hash algorithm are provided. An RFID tag includes a memory unit storing a tag's secret information and a group's secret information and a hash chain computation unit encrypting secret information based on a hash algorithm. The tag authentication apparatus includes a DB storing information about RFID tags, which is classified into groups and includes each group's secret information and each tag's secret information; a group's secret information search unit finding a group to which a tag to be authenticated belongs; and a tag's secret information search unit searching tags' secret information included in the found group.

Abstract: 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.

Abstract: 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.

Abstract: An apparatus and method for hybrid multiplication in GF(2m) by which trade-off between the area and the operation speed of an apparatus for a hybrid multiplier in finite field GF(2m) can be achieved are provided.