Deployment model

The Ledger is a blockchain platform based on Hyperledger Sawtooth technologies. Its purpose is essentially to allow the formalization of links between users, datasets and sharing agreements. Its hosting mode aligns well with the decentralized approach of the Orchestrator and allows operation by several independent partners.

Despite the decentralized deployment approach, access to the blockchain is through a middleware application and not directly in the way cryptocurrencies are. In this sense, access key security should be ensured by limiting the entry points to a single external api. This bridge constrains potential access paths and limits attack surfaces on the blockchain. It also allows better control of version migrations of the different components and avoids regression bugs by controlling potential usage scenarios.


The notion of assets on a blockchain is slightly different from a typical financial asset. In the case of the Ledger, an asset is defined as four distinct elements.

  1. The Dataset
    A dataset on Commons network should be viewed more as a data stream in that new versions of the dataset can be propagated in near real time to subscribing partners. The dataset thus becomes a recognized reality on the Ledger from the moment it is made available to a partner or made publicly visible. 
  2. License artifact
    The licensing artifact is one of the two main outputs of the Let's Agree application. The purpose of this artifact is to determine the rights and limitations associated with the use of a dataset to which a partner could subscribe. The artifact is formalized and associated with a specific dataset in order to determine an access modality.
  3. Governance artifact
    The governance artifact is used to instruct the Commons application on the technical constraints imposed on the source in order to ensure that the data is compatible with the sharing. The constraints are recorded in the General Ledger to track the type of transformations performed on the data and to provide better traceability and transparency on the activities performed. Some inter-organizational agreements require this type of visibility to enable a partnership. 
  4. The Digital Agreement
    The digital agreement is an associative link between a user account, an artifact, a dataset and by extension the owner of the dataset. It provides evidence of the acceptance of a specific agreement at a given time by an account. It demonstrates that the account in question is accessing the dataset with knowledge of the limitations and rights assigned to it and accepts these conditions. In this context, an agreement could be subject to change and would require a re-acceptance of the constraints in order to continue using the data.