摘要:
A method of verifying the authenticity of a message transmitted from a sender to a receiver in a communication system is partitioned into three stages. In the first stage, a key is secretly exchanged between the sender and receiver. This key is a binary irreducible polynomial p(x) of degree n. In addition, the sender and receiver share an encryption key composed of a stream of secret random, or pseudo-random bits. In the second stage, the sender appends a leading non-zero string of bits, which, in the simplest case, may be a single "1" bit, and n tail bits "0" to M to generate an augmented message, this augmented message considered as a polynomial having coefficients corresponding to the message bits. If the length of the message is known and cryptographically verified, then there is no need for a leading "1". The sender then computes a polynomial residue resulting from the division of the augmented message polynomial generated by the key polynomial p(x) exchanged by the sender and receiver. The sender encrypts the computed residue. Preferably, the encryption is done by performing a bitwise Exclusive OR operation between the bits of the residue and the stream of secret bits shared by the sender and receiver. The sender then transmits the message M and the encrypted residue. The third stage is performed by the receiver by decrypting the transmitted encrypted residue at the time of reception. The receiver then appends the decrypted residue to the end of the received message M to obtain a combined bit stream M'. The receiver computes the residue of the division between the binary polynomial represented by the bit stream M' and the key polynomial p(x) exchanged by the sender and receiver. The receiver accepts a received message M as authentic only if the residue computed is zero.
摘要:
In a communications system, a method is described allowing two users having established a communication session identified by a unique session freshness proof, to transmit and validate a new value of a variable by using an exchange certificate which combines the following elements: the new value of the variable, a common secret key known by both users, an exchange counter representative of the number of values of said variable transmitted between the two users during the current communication session and a session freshness proof. Protection against potential eavesdroppers and intruders is provided by combining cryptographically the elements of the exchange certificate. Further protection is obtained by interrupting the current communication session and opening a new one characterized by a new unique session freshness proof when the exchange counter reaches its maximum value; thus avoiding the risk that the same value of the session freshness keeps being used when the exchange counter is reset to its initial value. Consequently a given pair of values of the session freshness proof and of the exchange counter will never be used more than one time, making eavesdropping and, replaying attacks from intruders more difficult. Preferably, the method used for opening a new communication session uses already known authentication methods based on the common secret key.
摘要:
This invention deals with a safe key distribution and authentication in a data communication network (e.g. wireless LAN type of network).The network includes a network manager to which are connected, via a LAN wired circuit, one or more base stations. Individual remote stations are, in turn, wirelessly connected to an installed base station.One essential function for achieving security in such a network, is a mechanism to reliably authenticate the exchanges of data between communicating parties. This involves the establishment of session keys, which keys need to be distributed safely to the network components. An original and safe method is provided with this invention for key distribution and authentication during network installation, said method including using the first installed base station for generating a network key and a backbone key, and then using said first installed base station for subsequent remote station or additional base station installations while avoiding communicating said network key.
摘要:
A method and apparatus for providing authentication among a dynamically selected group of users in a communication system with a dynamically changing network topology. With this invention, freshness information and alleged identity information are transmitted from each of the users in the group using available paths in the network. A group key is then generated, and coded information, derived from the group key and the above transmitted information, is sent to each of the users. Each unit of coded information is accompanied by an identifying tag so as to identify which of the users is to use the appropriate unit of coded information. Each alleged user will then extract the group key from a corresponding coded information unit only if it shares an appropriate secret with a server. Without knowledge of the group key, a user cannot be authenticated.
摘要:
A method and system for detecting authorized programs within a data processing system. The present invention creates a validation structure for validating a program. The validation structure is embedded in the program and in response to an initiation of the program, a determination is made as to whether the program is an authorized program. The determination is made using the validation structure.
摘要:
A method and system for detecting authorized programs within a data processing system. The present invention creates a validation structure for validating a program. The validation structure is embedded in the program and in response to an initiation of the program, a determination is made as to whether the program is an authorized program. The determination is made using the validation structure.
摘要:
Method and apparatus for authenticating users (entities) of a computer network based on the entity's identification is described. Keys for each party of a potential session are derived by projections stored at each party's location. The projections are based on a partially computed function which can be in encryption by some key of the user identification or a multivariable polynomial or other function which is partially evaluated for one user's identification. Each user evaluates his projection with the other user/party's identification. The evaluated quantities are compared using a validation routine. The method requires only one basic piece of information, the projection to be distributed to each user, and does not need specific keys for specific users (or other users' information stored in one user's memory or global network). The method enables adding users to the system directory in a flexible way, without having to notify users of the addition. The method applies to communication heirarchies and inter-domain communication, as well.
摘要:
In a communications system comprising a number of base stations, each base station communicating over a shared communication channel with a plurality of registered stations and controlling the network cell formed by said plurality of registered stations, a method is described for dynamically registering and deregistering mobile stations. Each station owns a unique address and is allocated a local identifier at registration time. Each network cell owns a unique cell identifier known to all registered stations belonging to this network cell. Base stations manage cell members data uniquely associating the unique address and the local identifier corresponding to each one of the mobile stations belonging to their network cell. A registration request is sent to a selected base station by a registering mobile station, comprising the unique cell identifier of the network cell controlled by the selected base station and the unique address of the registering mobile station; the selected base station detects in its cell members data any conflicting registered station whose unique address matches the unique address of the registering mobile station and sends an address check packet to any conflicting registered station, comprising the unique address of the conflicting registered station, its local identifier and the identifier of the network cell it controls. A receiving registered mobile station sends to the selected base station, an acknowledgement to the address check packet if its unique address, the local identifier of its owning base station and its network cell identifier all match with the ones carried by the address check packet. The selected base station rejects the registration request it it receives an acknowledgement to its address check packet. The same address check packet is used to deregister inactive stations.
摘要:
A system for identifying the authorized receiver of any particular copy of a document. More specifically, each particular copy of a document is fingerprinted by applying a set of variations to a document, where each variation is a change in data contents, but does not change the meaning or perusal experience of the document. A database associating a set of variants to a receiver is maintained. Thus any variant or copy of that variant can be traced to an authorized receiver.
摘要:
A packet communications network in which multicast transmissions are made reliable by transmitting acknowledgements to all neighbors of every receiving node, including the source node. This allows the relinquishment of message holding buffers as soon as all near neighbors acknowledge receipt of the message after only tile longest round trip time to the nearest neighbors, rather than the round trip to the furthest destination. Moreover, highly reliable ancillary point-to-point transmission facilities can be used to retransmit multicast messages indicated as being lost by failure of acknowledgment. Finally, network partitions occurring during the multicast procedure do not necessarily lose the multicast message to the remote partitions since any node receiving the message can insure delivery to all other nodes in that partition.