公开(公告)号：AT235125T

公开(公告)日：2003-04-15

申请号：AT97307541

申请日：1997-09-25

Applicant: IBM

Inventor： COPPERSMITH DON ,  RAGHAVAN PRABHAKAR ,  ZIMMERMAN THOMAS G

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

Abstract: 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.

公开(公告)号：CA1328129C

公开(公告)日：1994-03-29

申请号：CA572708

申请日：1988-07-21

Applicant: IBM

Inventor： BRACHTL BRUNO ,  COPPERSMITH DON ,  HYDEN MYRNA ,  MATYAS STEPHEN JR ,  MEYER CARL ,  OSEAS JONATHAN ,  PILPEL SHAIY ,  SCHILLING MICHAEL

IPC: H04L9/32 ,  H04L9/06

Abstract: DATA AUTHENTICATION USING MODIFICATION DETECTION CODES BASED ON A PUBLIC ONE WAY ENCRYPTION FUNCTION A cryptographic method and apparatus are disclosed which transform a message of arbitrary length into a block of fixed length (128 bits) defined modification detection code (MDC). Although there are a large number of messages which result in the same MDC, because the MDC is a many to-one function of the input, it is required that it is practically not feasible for an opponent to find them. In analyzing the methods, a distinction is made between two types of attacks, i.e., insiders (who have access to the system) and outsiders (who do not). The first method employs four encryption steps per DEA block and provides the higher degree of security. Coupling between the different DEA operations is provided by using the input keys also as data in two of the four encryption steps. In addition, there is cross coupling by interchanging half of the internal keys. Although this second coupling operation does not add to security in this scheme, it is mandatory in the second method, which employs only two encryption steps per DEA block to trade off security for performance. By providing key cross-coupling in both schemes, an identical kernel is established for both methods. This has an implementation advantage since the first method can be achieved by applying the second method twice. The MDC, when loaded into a secure device, authorizes one and only one data set to be authenticated by the MDC, whereas methods based on message authentication codes or digital signatures involving a public key algorithm authorize a plurality of data sets to be authenticated. The MDC therefore provides for greater security control.

公开(公告)号：DE69719919T2

公开(公告)日：2003-12-18

申请号：DE69719919

申请日：1997-09-25

Applicant: IBM

Inventor： COPPERSMITH DON ,  RAGHAVAN PRABHAKAR ,  ZIMMERMAN THOMAS G

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

Abstract: 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.

公开(公告)号：DE69431390D1

公开(公告)日：2002-10-24

申请号：DE69431390

申请日：1994-11-09

Applicant: IBM

Inventor： COPPERSMITH DON ,  ROGAWAY PHILLIP W

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

Abstract: 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.

公开(公告)号：DE19960047A1

公开(公告)日：2000-08-17

申请号：DE19960047

申请日：1999-12-14

Applicant: IBM

Inventor： CHARI SURESH NARAYANA ,  COPPERSMITH DON ,  SCHERZER HELMUT ,  ROHATQI PANKAJ ,  WEINGART STEVE HARRIS ,  WITZEL MARTIN

IPC: G07F7/10 ,  H04L9/06 ,  H04L9/28 ,  G06K19/073 ,  H04L12/22

Abstract: Information is transformed before completing cryptographic process by applying N:N operation on elements of information in which case every element of information is combined with exactly corresponding element of transformed information. Cryptographic process is combined with transformed information. Inverse process is performed by applying inverse N:N operation on transformation and cryptographic processed information. Independent claims are included for: (a) a data media that can be used by an cryptographic information processing system (b) an information processing system (c) a chip card

公开(公告)号：CA1285650C

公开(公告)日：1991-07-02

申请号：CA490980

申请日：1985-09-18

Applicant: IBM

Inventor： COPPERSMITH DON ,  KITCHENS BRUCE P

IPC: H03M7/14 ,  H03M5/14 ,  G11B20/14 ,  H03M7/40 ,  H04L25/49

Abstract: YO984052 RUN-LENGTH LIMITED CODE WITHOUT DC LEVEL 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 runlength 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.