Method and system for managing shared information

A system for managing shared information which is shared between communication devices in a communication system, wherein each of the communication devices comprises:

• a shared information generator for generating the shared information;
• a memory for storing the shared information;
• a manager for communicating identifying information with another communication device to make an association with same piece of the shared information generated in the other communication device, wherein the identifying information identifies said piece of the shared information;
• and
• a storage section for storing associated pieces of the shared information,
• wherein the shared information is generated at each of the communication devices by:
• original information being transmitted in first data processing units from one of the communication devices to the other communication device by using a low power channel and a normal power channel that defines beginning and ending points of separate frames of the original information being transmitted;
• and
• the shared information being generated in second data processing units at each of the communication devices based on information which was received in the first data processing units by the other communication device by using a normal power channel, wherein the shared information in the second data processing units is stored in the storage section of the other communication device,
• wherein the associated pieces of the shared information at respective ones of the communication devices are stored in the respective storage sections of the communication devices.

A communication device for managing shared information which is shared with another communication device, comprising:

• a shared information generator for generating the shared information;
• a memory for storing the shared information;
• a manager for communicating identifying information with another communication device to make an association with same piece of the shared information generated in the other communication device, wherein the identifying information identifies said piece of the shared information, the identifying information indicating which bits of a plurality of bits of the shared information were successfully received over a low power channel;
• and
• a storage section for storing associated pieces of the shared information, the associated pieces of the shared information including bit levels of a plurality of bits of the shared information that were not successfully received over the low power channel and that are sent over a normal power channel.

A computer readable medium storing a program for instructing a computer to manage shared information which is shared with another communication device, comprising:

• storing the shared information in a memory;
• communicating identifying information with another communication device through a communication section to make an association with same piece of the shared information generated in the other communication device, wherein the identifying information identifies said piece of the shared information, the identifying information indicating which bits of a plurality of bits of the shared information were successfully received over a low power channel;
• and
• storing associated pieces of the shared information in a storage section, the associated pieces of the shared information including bit levels of a plurality of bits of the shared information that were not successfully received over the low power channel and that are sent over a normal power channel.

A communication system for secret communication between first and second communication devices, wherein

• the first communication device comprises:
• a first generator for generating secret information to be shared with the second communication device;
• a first memory for storing the secret information;
• a first manager for transmitting identifying information to the second communication device to make an association with same piece of the secret information generated in the second communication device, wherein the identifying information identifies said piece of the secret information;
• and
• a first storage section for storing associated pieces of the secret information, and
• the second communication device comprises:
• a second generator for generating the secret information to be shared with the second communication device;
• a second memory for storing the secret information;
• a second manager for using the identifying information received from the first communication device to make an association with the same piece of the secret information generated in the first communication device, the identifying information indicating which bits of a plurality of bits of the shared information were successfully received over a low power channel;
• and
• a second storage section for storing associated pieces of the secret information, the associated pieces of the secret information including bit levels of a plurality of bits of the shared information that were not successfully received over the low power channel and that are sent over a normal power channel.