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22 条记录 (耗时 0.022 秒)

    Run-length limited code without DC level
    1.
    发明授权
    Run-length limited code without DC level 失效
    运行长度限制代码，无直流电平

    公开(公告)号：US4675650A

    公开(公告)日：1987-06-23

    申请号：US725954

    申请日：1985-04-22

    申请人： Don Coppersmith ,  Bruce P. Kitchens

    发明人： Don Coppersmith ,  Bruce P. Kitchens

    IPC分类号： H03M7/14 ,  H03M5/14 ,  H03M7/42

    CPC分类号： H03M5/145

    摘要： Code modification circuitry alters the end portion of each block in a sequence of code blocks, and also inserts additional bits at the junction between contiguous blocks. The codes to be processed are run-length limited (RLL) codes having a DC component which is to be removed for certain applications such as magnetic recording. The modification circuitry retains the RLL format. Charge (or the integral of the waveform) accumulated by the sequence of bits of one block is compensated by selecting the sense of charge accumulation in next block to be of opposite sense. This is accomplished by the code modification circuitry using a relatively small set of possible combinations of digital words at the junctions of the blocks.

    摘要翻译： 代码修改电路以一系列代码块改变每个块的结尾部分，并且在相邻块之间的连接处插入附加位。 要处理的代码是具有DC分量的游程长度限制（RLL）代码，其将针对某些应用例如磁记录被去除。 修改电路保留RLL格式。 通过在下一个块中选择具有相反意义的电荷累积感来补偿由一个块的位序列积累的电荷（或波形的积分）。 这通过代码修改电路使用在块的结点处的数字字的可能组合的相对较小的集合来实现。

    Software-efficient pseudorandom function and the use thereof for decryption
    3.
    发明授权
    Software-efficient pseudorandom function and the use thereof for decryption 失效
    软件效率的伪随机函数及其解密的用途

    公开(公告)号：US5835597A

    公开(公告)日：1998-11-10

    申请号：US831463

    申请日：1997-03-31

    申请人： Don Coppersmith ,  Phillip W. Rogaway

    发明人： Don Coppersmith ,  Phillip W. Rogaway

    IPC分类号： G09C1/00 ,  G06F12/14 ,  G06F21/00 ,  G06F21/24 ,  H04L9/18 ,  H04L9/22 ,  H04L9/00

    CPC分类号： G06F21/31 ,  G06F21/46 ,  G06F21/602 ,  G06F21/62 ,  G06F21/72 ,  G06F21/80 ,  G06F21/85 ,  H04L9/0656 ,  G06F2211/007 ,  H04L2209/046

    摘要： A software-efficient pseudorandom function maps an index and an encryption key to a pseudorandom bit string useful for constructing a stream cipher. The method begins by preprocessing the encryption key into a table of pseudorandom values. The index and a set of values from the table is then used to generate a set of initial values for the registers. At least some of the register values are modified in part by taking a current value of a register and replacing the current value with a function of the current value and a value retrieved from the table, the latter value being determined by the values in one or more other registers. After modifying the register values in this fashion, the values are masked using other values from the table and the results then concatenated into the pseudorandom bit string. The modification step is repeated and a new masked function of the register values is then concatenated into the pseudorandom bit string. The modification and concatenation steps are repeated to continue growing the pseudorandom bit string until the string reaches some desired length.

    摘要翻译： 软件效率的伪随机函数将索引和加密密钥映射到用于构建流密码的伪随机比特串。 该方法开始于将加密密钥预处理成伪随机值的表。 然后使用索引和表中的一组值来生成一组寄存器的初始值。 至少一些寄存器值被部分修改，取当前的寄存器值，并用当前值的函数和从表中检索的值替换当前值，后一个值由一个或多个值中的值确定 更多其他寄存器。 以这种方式修改寄存器值后，使用表中的其他值对值进行掩码，然后将结果并入到伪随机位串中。 修改步骤被重复，并且寄存器值的新的掩蔽函数然后被连接到伪随机位串中。 重复修改和连接步骤以继续生长伪随机位串，直到字符串达到期望的长度。

    System and method for near-field human-body coupling for encrypted communication with identification cards
    4.
    发明授权
    System and method for near-field human-body coupling for encrypted communication with identification cards 失效
    用于与识别卡进行加密通信的近场人体耦合的系统和方法

    公开(公告)号：US5796827A

    公开(公告)日：1998-08-18

    申请号：US749865

    申请日：1996-11-14

    申请人： Don Coppersmith ,  Prabhakar Raghavan ,  Thomas G. Zimmerman

    发明人： Don Coppersmith ,  Prabhakar Raghavan ,  Thomas G. Zimmerman

    IPC分类号： G06K19/07 ,  B60R25/00 ,  G06K7/08 ,  G06K17/00 ,  G06K19/04 ,  G06K19/077 ,  G06K19/10 ,  G07C9/00 ,  H04B5/00 ,  H04B5/02 ,  H04B13/00 ,  H04L9/32 ,  H04L9/00

    CPC分类号： A61B5/0024 ,  A61B5/0028 ,  B60R25/2027 ,  G06K19/041 ,  G06K19/07749 ,  G06K19/07758 ,  G06K19/07788 ,  G06K7/10326 ,  G06Q20/4012 ,  G07C9/00111 ,  H04B13/005 ,  H04L9/3226 ,  H04L9/3297 ,  H04L2209/56 ,  H04L2209/805

    摘要： An apparatus and method are disclosed for encoding and transferring data from a transmitter to a receiver, using the human body as a transmission medium. The transmitter includes an electric field generator, a data encoder which operates by modulating the electric field, and electrodes to couple the electric field through the human body. The receiver includes electrodes, in physical contact with, or close proximity to, a part of the human body, for detecting an electric field carried through the body, and a demodulator for extracting the data from the modulated electric field. An authenticator, connected to the receiver, processes the encoded data and validates the authenticity of the transmission. The apparatus and method are used to identify and authorize a possessor of the transmitter. The possessor then has secure access to, and can obtain delivery of, goods and services such as the distribution of money, phone privileges, building access, and commodities. Encryption provides rapid transmission and authentication of the transmitter, and a plurality of similar transmitters, with minimum vulnerability to counterfeit. Signal processing and digital communication components accommodate variations in location and orientation of the transmitter and receiver, and provide transmitters with long life times and high reliability.

    摘要翻译： 公开了一种用于使用人体作为传输介质来将数据从发射机编码和传送到接收机的装置和方法。 发射机包括电场发生器，通过调制电场操作的数据编码器，以及将电场耦合通过人体的电极。 接收机包括与身体的一部分物理接触或接近的电极，用于检测通过身体携带的电场，以及用于从调制电场中提取数据的解调器。 连接到接收器的认证器处理编码数据并验证传输的真实性。 该装置和方法用于识别和授权发射机的拥有者。 拥有者然后可以安全地访问和可以获得货物和服务的交付，例如货币分配，电话特权，建筑物访问和商品。 加密提供了对发射机和多个类似的发射机的快速传输和认证，并且具有最小的假冒易损性。 信号处理和数字通信组件适应发射机和接收机的位置和方向的变化，并提供具有长寿命和高可靠性的发射机。

    Method for finding a best test for a nominal attribute for generating a binary decision tree
    8.
    发明授权
    Method for finding a best test for a nominal attribute for generating a binary decision tree 失效
    找到用于生成二进制决策树的名义属性的最佳测试的方法

    公开(公告)号：US6101275A

    公开(公告)日：2000-08-08

    申请号：US13147

    申请日：1998-01-26

    申请人： Don Coppersmith ,  Se June Hong ,  Jonathan R. M. Hosking

    发明人： Don Coppersmith ,  Se June Hong ,  Jonathan R. M. Hosking

    IPC分类号： G06K9/62 ,  G06K9/36 ,  G06K9/46 ,  G06K9/68

    CPC分类号： G06K9/6282

    摘要： A fast way for determining the best subset test for a nominal attribute in a decision tree. When a nominal attribute has n distinct values, the prior art requires computing the impurity functions on each of the 2.sup.n-1 -1 possible subset partitioning of the n values and finding the minimum case among them. This invention guarantees the minimum impurity test on the attribute by computing only (n-1) impurity function computations. This reduction of computational complexity makes it practically possible to find the true best tests for many real data mining application, where a binary decision tree is used as the classification model.

    摘要翻译： 确定决策树中名义属性的最佳子集测试的快速方法。 当标称属性具有n个不同的值时，现有技术需要在n个值的2n-1-1个可能子集划分中的每一个上计算杂质函数，并且找出其中的最小值。 本发明通过仅计算（n-1）杂质函数计算来保证对属性的最小杂质测试。 这种计算复杂度的降低使得实际上可以为许多实际数据挖掘应用找到真正的最佳测试，其中使用二进制决策树作为分类模型。

    Authentication system using one-time passwords
    9.
    发明授权
    Authentication system using one-time passwords 失效

    公开(公告)号：US5592553A

    公开(公告)日：1997-01-07

    申请号：US597376

    申请日：1996-02-08

    申请人： Richard H. Guski ,  Raymond C. Larson ,  Stephen M. Matyas, Jr. ,  Donald B. Johnson ,  Don Coppersmith

    发明人： Richard H. Guski ,  Raymond C. Larson ,  Stephen M. Matyas, Jr. ,  Donald B. Johnson ,  Don Coppersmith

    IPC分类号： G09C1/00 ,  G06F1/00 ,  G06F21/00 ,  H04L9/32 ,  H04L12/22 ,  H04L29/06

    CPC分类号： H04L63/0838 ,  G06F21/31 ,  H04L12/22 ,  H04L63/0846 ,  H04L9/0822 ,  H04L9/088 ,  H04L9/0894 ,  H04L9/3228 ,  H04L2209/20

    摘要： A system for authenticating a user located at a requesting node to a resource such as a host application located at an authenticating node using one-time passwords that change pseudorandomly with each request for authentication. At the requesting node a non-time-dependent value is generated from nonsecret information identifying the user and the host application, using a secret encryption key shared with the authenticating node. The non-time-dependent value is combined with a time-dependent value to generate a composite value that is encrypted to produce an authentication parameter. The authentication parameter is reversibly transformed into an alphanumeric character string that is transmitted as a one-time password to the authenticating node. At the authenticating node the received password is transformed back into the corresponding authentication parameter, which is decrypted to regenerate the composite value. The non-time-dependent value is replicated at the authenticating node using the same nonsecret information and encryption key shared with the requesting node. The locally generated non-time-dependent value is combined with the regenerated composite value to regenerate the time-dependent value. The user is authenticated if the regenerated time-dependent value is within a predetermined range of a time-dependent value that is locally generated at the authenticating node.

    Method and apparatus for cryptographically transforming an input block into an output block
    10.
    发明授权
    Method and apparatus for cryptographically transforming an input block into an output block 失效
    用于将输入块加密地变换成输出块的方法和装置

    公开(公告)号：US06301362B1

    公开(公告)日：2001-10-09

    申请号：US09096615

    申请日：1998-06-12

    申请人： Stephen M. Matyas, Jr. ,  Don Coppersmith ,  Donald B. Johnson

    发明人： Stephen M. Matyas, Jr. ,  Don Coppersmith ,  Donald B. Johnson

    IPC分类号： H04L906

    CPC分类号： H04L9/002 ,  H04L9/0625 ,  H04L2209/24

    摘要： A method and apparatus for cryptographically transforming an input block into an output block. The input block has a first block size and is partitionable into a plurality of input subblocks having a second block size that is a submultiple of the first block size. To encrypt or decrypt, the input subblocks are passed through respective first substitution functions controlled by one or more keys to generate a first plurality of modified subblocks. The first plurality of modified subblocks are then passed through a mixing function to generate a second plurality of modified subblocks, each of which depends on each of the first plurality of modified subblocks. Finally, the second plurality of modified subblocks are passed through respective second substitution functions controlled by one or more keys to generate a plurality of output subblocks that are combinable into an output block.

    摘要翻译： 一种用于将输入块密码变换为输出块的方法和装置。 输入块具有第一块大小并且可分割成具有第二块大小的多个输入子块，该第二块大小是第一块大小的次数。 为了加密或解密，输入子块通过由一个或多个键控制的相应的第一替换函数，以产生第一多个修改的子块。 第一多个经修改的子块然后被传递通过混合功能以产生第二多个修改的子块，每个子块依赖于第一多个修改子块中的每一个。 最后，第二多个经修改的子块通过由一个或多个密钥控制的相应的第二替换函数，以产生可组合成输出块的多个输出子块。