An Online Threshold Key Distribution Scheme for Symmetric Key Management

The threshold secret sharing technique has been used extensively in cryptography. This technique is used for splitting secrets into shares and distributing the shares in the network to provide protection against attacks and to reduce the possibility of loss of information. In this paper, a new approach is introduced to enhance communication security among the nodes in a network based on the threshold secret sharing technique and traditional symmetric key management. The proposed scheme aims to enhance the security of the symmetric key distribution in the network. In the proposed scheme, key distribution is online which means key management is conducted whenever a message needs to be communicated. The basic idea is encrypting a message with a key (the secret) at the sender, then splitting the key into shares and sending the shares from different paths to the destination. Furthermore, a pre-distributed shared key scheme is utilized for more secure transmissions of the secret’s shares. The proposed scheme, with the exception of some offline management by the network controller, is distributed, i.e., the symmetric key setups and the determination of the communication paths is preformed in the nodes. This approach enhances communication security among the nodes in a network that operates in hostile environments. The security analyses of the proposed scheme are