US 5,966,449 AGranted

Method and network for communicating between a group of entities a text encrypted using an encryption key intrinsic to the group of entities in a network having a plurality of entities and a center

AssigneeCanon Kabushiki Kaisha

InventorsKeiichi Iwamura, Takahisa Yamamoto

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Abstract

In a network having a plurality of entities and a center, the center creates random numbers for all the combinations of two of the entities within the network, and delivers to each entity random numbers created for those combinations involving that entity. A sender entity selects a random number corresponding to the combination of that entity and the destination entity from a group of random numbers delivered to the sender entity, encrypts a communication text using an encryption key determined by the selected random number and sends the encrypted text to the destination entity. The destination entity selects a random number corresponding to the combination of itself and the sender entity from the random numbers delivered to the destination entity, and decodes a cipher text received using an encryption key determined by the selected random number.

Claims36

Dependent claims

A communication method for communication between entities in a network having a plurality of entities and a center, comprising the steps of:

said center converting one-to-one identifiers of the plurality of entities into identification numbers, respectively, in terms of a predetermined function;
said center creating pieces of information which are independent of one another for all combinations composed of two of the identification numbers;
said center delivering to each entity a group of pieces of information created for combinations of two identification numbers involving an identification number obtained by converting an identifier of that entity;
a sender entity converting an identifier of a destination entity into an identification number thereof in terms of the predetermined function, selecting information corresponding to the identification number of said destination entity obtained by conversion from a group of pieces of information delivered to the sender entity, encrypting a communication text using an encryption key depending on the selected information corresponding to the identification number of said destination entity, and sending encrypted text to said destination entity;
and
said destination entity receiving the encrypted text, converting an identifier of said sender entity into an identification number thereof in terms of the predetermined function, selecting information corresponding to the identification number of said sender entity obtained by conversion from the group of pieces of information delivered to the destination entity, and decoding the encrypted text using an encryption key depending on the selected information corresponding to the identification number of said sender entity.

3 more elements

A communication method for communication between entities in a network having a plurality of entities and a center, comprising the steps of:

said center converting one-to-one identifiers of said plurality of entities into identification numbers, respectively, in terms of a predetermined function and dividing each of the identification numbers at every nth digit, where n is a predetermined number, to produce portions of those identification numbers;
said center creating pieces of information which are independent of one another for all combinations composed of two numbers from among the portions of the identification numbers;
said center delivering to each entity a group of pieces of information created for combinations of two identification numbers involving the values of portions of the identification number obtained by converting the identifier of that entity, and dividing the converted identification number at every nth digit;
a sender entity converting an identifier of a destination entity into an identification number thereof in terms of the predetermined function, dividing the identification number at every nth digit to produce portions of that identification number, selecting information corresponding to portions of the identification number of said destination entity from a group of pieces of information delivered to the sender entity, encrypting a communication text using an encryption key depending on the selected information corresponding to the portions of the identification number of said destination entity, and sending encrypted text to said destination entity;
and
said destination entity receiving the encrypted text, converting an identifier of the sender entity into an identification number thereof in terms of the predetermined function, dividing the identification number at every nth digit to produce portions of that identification number, selecting information corresponding to portions of the identification number of said destination entity from the group of pieces of information delivered to the destination entity and decrypting the encrypted text using an encryption key depending on the selected information corresponding to the portions of the identification number of said sender entity.

3 more elements

A communication method between groups of a predetermined number of entities in a network having a plurality of entities and a center, comprising the steps of:

said center converting one-to-one identifiers of said plurality of entities into identification numbers, respectively, in terms of a predetermined function;
said center creating pieces of information which are independent of one another for all combinations composed of the predetermined number of the identification numbers;
said center delivering to each entity a group of pieces of information created for combinations of two identification numbers involving an identification number obtained by converting an identifier of a respective entity;
a sender entity converting identifiers of destination entities into respective identification numbers in terms of the predetermined function, selecting information corresponding to a combination of the identification numbers of said destination entities obtained by conversion from a group of pieces of information delivered to the sender entity, encrypting a communication text using an encryption key depending on the selected information corresponding to the identification numbers of said destination entities, and sending encrypted text to said destination entities;
and
each of said destination entities receiving the encrypted text converting the identifiers of other entities in the group into respective identification numbers in terms of the predetermined function, selecting information corresponding to a combination of the identification numbers of the other entities obtained by conversion from the group of pieces of information delivered to respective destination entities, and decrypting the encrypted text using an encryption key depending on the selected information corresponding to the-identification numbers of the other entities.

3 more elements

A communication network having a plurality of entities and a center, wherein said center comprises:

conversion means for converting one-to-one identifiers of said plurality of entities into identification numbers, respectively, in terms of a predetermined function;
creating means for creating pieces of information which are independent of one another for all combinations composed of two of the identification numbers;
and
delivering means for delivering to each entity a group of pieces of information created for combinations of two identification numbers involving an identification number obtained by converting an identifier of that entity,
and said each entity comprising:
sender means for converting an identifier of a destination entity into an identification number thereof in terms of the predetermined function, selecting information corresponding to the identification number of the destination entity obtained by conversion from a group of pieces of information delivered to the sender entity, encrypting a communication text using an encryption key depending on the selected information corresponding to the identification number of the destination entity, and sending encrypted text to said destination entity;
and
receiver means for receiving the encrypted text, converting an identifier of a sender entity into an identification number thereof in terms of the predetermined function, selecting information corresponding to the identification number of the sender entity obtained by conversion from the group of pieces of information delivered to the destination entity, and decoding the encrypted text using an encryption key depending on the selected information corresponding to the identification number of the sender entity.

5 more elements

A network having a plurality of entities and a center, wherein said center comprises:

conversion means for converting one-to-one identifiers of said plurality of entities into identification numbers, respectively, in terms of a predetermined function and dividing each of the identification numbers at every nth digit, where n is a predetermined number;
creating means for creating pieces of information which are independent of one another for all combinations composed of two numbers of the predetermined digits which are portions of identification numbers being divided at every nth digit;
delivering means for delivering to each entity a group of pieces of information created for combinations of two identification numbers involving the values of portions of the identification number obtained by converting the identifier of that entity being divided at every nth digit,
and each said entity comprising:
sender means for converting the identifier of a destination entity into an identification number thereof in terms of the predetermined function, dividing the identification number at every nth digit, selecting information corresponding to the portions of the identification number of said destination entity divided at every nth digit from a group of pieces of information delivered to the sender entity, encrypting a communication text using an encryption key depending on the selected information corresponding to the portions of the identification number of said destination entity, and sending encrypted text to the destination entity;
and
receiver means for receiving the encrypted text, converting an identifier of the sender entity into an identification number in terms of said predetermined function, dividing the identification number at every nth digit, selecting information corresponding to portions of the identification number of said destination entity divided at every nth predetermined digit from the group of pieces of information delivered to the destination entity and decoding the encrypted text using an encryption key depending on the selected information corresponding to the portions of the identification number of said sender.

4 more elements

A network having a plurality of entities and a center, wherein said center comprises:

conversion means for converting one-to-one identifiers of said plurality of entities into identification numbers, respectively, in terms of a predetermined function;
creating means for creating pieces of information which are independent of one another for all combinations composed of a predetermined number of the identification numbers;
and
delivering means for delivering to each entity a group of pieces of information created for combinations of two identification numbers involving an identification number obtained by converting the identifier of that entity,
and each said entity comprising:
sender means for converting identifiers of destination entities into respective identification numbers in terms of said predetermined function, selecting information corresponding to a combination of the identification numbers of said destination entities obtained by conversion from a group of pieces of information delivered to the sender entity, encrypting a communication text using an encryption key depending on the selected information corresponding to the identification numbers of said destination entities, and sending encrypted text to the destination entities;
and
receiver means for receiving encrypted text, converting the identifiers of other entities within the group into respective identification numbers in terms of said predetermined function, selecting information corresponding to a combination of the identification numbers of those other entities obtained by conversion from the group of pieces of information delivered to respective destination entities, and decoding the encrypted text using an encryption key depending on the selected information corresponding to the identification numbers of the other entities.

5 more elements

Dependencies are inferred from the claim text.