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Trustchain: Proof of Guarantee and Reputation (POGR): A lightweight, eco-efficient and fair consensus

Domain Digital

Technologies Secure Communications
Strong authentication


The problem addressed by the invention is the energy consumption and the lack of fairness in the existing consensus, the correlation between off-chain trust (real world) and on-chain trust (the blockchain system).

Innovative solution

An online/offline trading platform based on warranty and reputation.

  • A lightweight consensus called Proof of Guarantee and Reputation (PoGR) which requires little computation and can ensure fairness between nodes using a score based on guarantee and reputation.
  • An efficient trust/reputation model that allows the assessment of each participant's trust in the system.
  • An incentive mechanism that uses collateral and reputation to control participant behavior.


The cases of use of decentralized marketplace (online market), local currency or escrow account type blockchains have been identified with the help of a market player but other areas using the blockchain and facing trust issues may be referred to.

How it works

The platform ensures the registration of transactions, but also the provision of offline services. A mathematical model makes it possible to calculate the level of confidence of each participant in the system. A reputation-based and collateral-based incentive mechanism controls participant behavior. The proposed trust model not only helps buyers to select services provided by sellers, but also allows credible participants to launch nodes and create updates, thus contributing to CB management. The platform is based on the consensus called Proof Guarantee and Reputation (PoGR). PoGR selects nodes based on a rating formula that uses three parameters: reputation, amount deposited, and risk taken. This formula is designed to optimize the computation on each node. It also allows to have an equity between all the nodes of the system. The results of the security analysis and performance evaluation demonstrate the feasibility, effectiveness and scalability of our solution.

devlopment status (TRL 4)

  • The proposed consensus, implemented in the context of a free exchange platform (market place) supports both the registration of online transactions and the provision of offline services.
  • The mathematical model allows the calculation of the level of confidence of each participant in the system by assigning him a score which represents his level of reputation.
  • The reputation-based reward and punishment mechanism effectively controls participant behavior.
  • The trust mechanism helps buyers select services provided by sellers, and also allows the right participants to operate nodes and create updates fairly.
  • The proposed solution shows its ability to resist possible attacks.
  • Several scenarios to assess the effectiveness of the proposed trust model and the fairness of the PoGR were tested.
  • Other tests demonstrated the qualification of the system in terms of performance and scalability.


Computer Science, Image and Interaction Laboratory: L3i (La Rochelle University)


Patent project



We want to test our solution in a public blockchain to prove its effectiveness and security for business use cases.


Valérie SCHOEN


+337 62 10 02 73