Secret sharing is a mechanism of sharing confidential data among a group of members so that it can be reconstructed with the help of a certain number of members. There are various approaches to share and recover a secret securely. A trivial solution is to distribute the shares of secrets among a group of people and later reconstruct the secret by collecting the shares from all the people. This solution wasn't an efficient solution as all the members were needed to reconstruct the secret. A more efficient mechanism where only a certain number of shares of the secret needed to recover the secret was proposed and implemented. Shamir's Secret Sharing is one such popular scheme that achieves a secret sharing where only a certain threshold shares needed for the reconstruction
One common assumption for all these solutions is that there is a member who is responsible to recover all the shares by contacting each member that owns the share. This creates a number of limitations during the implementation including the trust during the reconstruction of the secret. In this invention, we are going to propose an approach where the secret sharing and the reconstruction takes place in an anonymous way by using the mechanism borrowed from of onion routing protocol.
Field of the Invention:
The present invention proposes a secure secret sharing mechanism where the responsibility to maintain the secret is distributed among the members and later reconstructed in an anonymous way without needing the recognization of each and every member who holds the share of secret reconstruction responsibility.
Application:
An ideal application of the proposed invention is in a decentralized ecosystem where a party wants to share a secret with the other party with the help of trustless members who are later responsible to reconstruct the shared secret. Any secret sharing application that doesn't want to disclose all the members during the secret reconstruction but wants to ensure security is the ideal candidate of the present invention.
Description of the Prior Art:
As the internet becomes more and more accessible through various portable devices, securing confidential information in a single place becomes more difficult. While storing confidential information at a single place creates a single point of failure issues, storing at multiple places exposes multiple attack points. Several secret sharing mechanisms have been invented to maintain such confidential information. In a well-known mechanism, the critical information is split into "n" shared data parts such that the secret data can be reconstructed when "k" or more of the "n" data parts are available. In particular, the method using polynomial interpolation or most commonly known as Shamir's Secret Sharing (SSS) is a widely used implementation.
Shamir’s secret mechanism allows us to securely share a secret among a group of “n” people and needs a certain threshold value of “k” shares of “n” shares to reconstruct the secret. This allows for a person with “k-1” shares to not be able to reconstruct the original secret.
Shortcomings of Prior Art:
Shamir's Secret Sharing mechanism is the widely used secret sharing mechanism as it provides a convenient way to reconstruct the secret with the help of a subset of members holding the share of the secret. Even though the process is impressive and has proved to be efficient, it has limitations when it is practically implemented.
Single point of failure
We know that in order for Shamir’s secret sharing mechanism to work, the secret must be split or reconstructed on a single device. And when the device is compromised during either of these operations the secret is accessible to the attacker. Practically, the attacker doesn’t need huge computational power to find all the shares needed for the reconstruction of the secret, all they need to do is find the master device where the secret is split or reconstruction is carried out and gain access to it.