Method and system for authentication and preserving the integrity of communication, secured by secret sharing

A system and method for providing secure communication between a source and a destination that is secured by secret sharing, during a vulnerability window in which all secret shares are collected in one or more points along the communication paths. Accordingly, during the regular operation of the communication protocol, a common random secret OTP is created by sending random bits from the sender to the receiver and the source is allowed to perform bitwise XOR operation between the information to be sent and the common random secret OTP, prior to using secret sharing. The results of the bitwise XOR operation are sent to the destination using secret sharing and the destination reconstructs the random secret and decrypts the received data, using the common established random secret. The common random secret is based on polynomial randomization being transferred from the source to the destination using secret sharing. The coefficients of a selected polynomial are randomly chosen at the sender side and are known both to the sender and the receiver. An x value is selected for each set of chosen coefficients, for which there is a corresponding y value. Pairs of x and y values transmitted from the sender to the receiver, where each pair represents a secret share. The transfer of polynomial randomization is repeated for every bit/byte or for any group of bits of the message to be transmitted, while in each time randomly choosing a different set of coefficients. At the end, the destination decrypts the message by collecting all shares being pairs of the received x and y values and reconstructs the selected polynomial from all collected shares.