METHOD AND SYSTEM FOR ENCRYPTION BY A PROXY

摘要

The invention concerns a method for transmitting messages between a transmitter and at least one receiver, comprising the following steps: encrypting the message (m) to be transmitted using a key (a) associated with said transmitter; sending the encrypted message in a conversion module comprising a conversion key (p_a?b) and a^{conversion function; converting the encrypted message received in the conversion module into an encrypted message capable of being decrypted by a key (b) specific to said receiver, said conversion being carried out without the initial message appearing in plain text in the conversion module; sending the converted message to said receiver; decrypting said transformed message received by said receiver using the specific key (b). The invention is characterized in that the conversion key (p_a?b) of the conversion module depends on a non-trivial value exponentiated to the value of the key (a) related to the transmitter and the key (b) related to the receiver. The invention also concerns a system for transmitting messages between a transmitter and at least one receiver, said system being configured to implement the inventive method.}