Institute for Information Industry

Other

Sung-Ming Yen

Chiung-Ying Huang

Jui-Ming Wu

Chien-Chung Yuan

Jong-Ming Lee

Jack Lee

Yen-Chang Chen

His-Chung Lin

Pao-Yu Kuo

Jheng-Hong Tu

Jia Jum Hung

An encryption method and decryption method are provided. The encryption method divides an electronic file into a plurality of message blocks, wherein the message blocks have a sequence. The encryption method sets a checking vector as the last message block. The encryption method performs the following steps on each message block according to the sequence: generating an input block, deriving an output block by encrypting the input block by an encryption key, and deriving an encrypted block by applying XOR operation to the output block and the previous message block, wherein the input block is equivalent to applying XOR operation to the message block, the output block corresponding to the previous message block, and the message block before the previous one. The encryption method generates an electronic encrypted file by concatenating the encrypted blocks. The decryption method performs a series of operations corresponding to the above operations.

Block encryption method and block decryption method having integrity verification

A system, a method, and a computer readable medium for micropayment with varying denomination are disclosed. The method utilizes a secret value, a public information, a number base parameter, a bit parameter, and merged one-way hash chains to calculate a root for providing a certificate of a transaction among a customer, a merchant and a service device. Therefore, the purpose of varying denomination for micropayment system can be achieved and the trade safety and the efficiency during the transaction process can be enhanced as well.

System, method, and computer readable medium for micropayment with varying denomination

Disclosed is an electronic payment device and its method using an balanced binary tree for calculating a first data X of current consumption or a plurality of root values R from an initial value X of the amount of money that user purchases. The first data X is correspondent to a position value j with a respective relation of j&equals;n&minus;k&plus;1. The first data X is generated according to the value of the binary code d d . . . d d of the position value j being a 0 or 1, by formula X &equals;h (. . . (h (h (X )))). If the binary code d &equals;0, i&equals;m&minus;1, m&minus;2, . . . , 1, 0, then the first one-way function h is used as an operating function. Otherwise, the second one-way function h is operated when the binary code d &equals;1. Moreover, a function operating device for an electronic payment using an balanced binary tree is also disclosed. The present invention requires less calculation than that in the prior art, and thus is more effective.

Electronic payment device using balanced binary tree and the method of the same

An electronic payment device and its method using an unbalanced binary tree are disclosed. The total unit n of the amount of money that user purchases is decomposed first into a Matrix of p rows&times;q columns. Then, a first one-way function h and a second one-way function h serve to define the one-way function operation of the first row and each column, respectively. When two numbers of operation times a and b are calculated by their formulas respectively, they are substituted into formula X &equals;h (h (X )). Namely, by the first one-way function h , a times of operation is performed, and then by the second one-way function h , b times of operation is performed, thus, a first data X of current consumption can be derived rapidly. The present invention has only a few times of operation, thus the calculating efficiency is improved greatly.

Electronic payment device using unbalanced binary tree and the method of the same

A cryptographic checksum apparatus is disclosed. This apparatus includes a keystream generator configured to generate a secret keystream according to a common secret key. The apparatus also includes a postfix circuit configured to augment postfix bits after an original message. Further, a demultiplexer is used to direct the postfixed message to one of the output terminals under the control of the secret keystream. A first mixer is connected to one output terminal of the demultiplexer, and a second mixer is connected to the other output terminal of the demultiplexer. Moreover, a first compression circuit is used to receive an output of the first mixer, wherein content of the first compression circuit is used as the first part of the checksum output. Similarly, a second compression circuit is used to receive an output of the second mixer, wherein content of the second compression circuit is used as the second part of the checksum output. Finally, a first transmission gate is connected to the second compression circuit, whose output bit is then transferred to the first mixer through the first transmission gate under control of the postfixed message bit. A second transmission gate is connected to the first compression circuit, whose output bit is then transferred to the second mixer through the second transmission gate under control of the postfixed message bit.

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Taipei, Taiwan

Sung-Ming Yen