RFC-0300/DAN

Digital Assets Network

status: draft

Maintainer(s): Cayle Sharrock and Philip Robinson

Licence

The 3-Clause BSD Licence.

Copyright 2018 The Tari Development Community

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  1. Redistributions of this document must retain the above copyright notice, this list of conditions and the following disclaimer.
  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.
  3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS DOCUMENT IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS", AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Language

The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY" and "OPTIONAL" in this document are to be interpreted as described in BCP 14 (covering RFC2119 and RFC8174) when, and only when, they appear in all capitals, as shown here.

Disclaimer

This document and its content are intended for information purposes only and may be subject to change or update without notice.

This document may include preliminary concepts that may or may not be in the process of being developed by the Tari community. The release of this document is intended solely for review and discussion by the community of the technological merits of the potential system outlined herein.

Goals

The aim of this Request for Comment (RFC) is to describe the key features of the Tari second layer, also known as the Digital Assets Network (DAN)

Related Requests for Comment

Description

Abstract

Digital Assets (DAs) are managed by committees of special nodes called Validator Nodes (VNs):

  • VNs manage digital asset state change and ensure that the rules of the asset contracts are enforced.
  • VNs form a peer-to-peer communication network that together defines the Tari DAN.
  • VNs register themselves on the base layer and commit collateral to prevent Sybil attacks.
  • Scalability is achieved by sacrificing decentralization. Not all VNs manage every asset. Assets are managed by subsets of the DAN, called VN committees. These committees reach consensus on DA state amongst themselves.
  • VNs earn fees for their efforts.
  • DA contracts are not Turing complete, but are instantiated by Asset Issuers (AIs) using DigitalAssetTemplates that are defined in the DAN protocol code.

Digital Assets

  • DA contracts are not Turing complete, but are selected from a set of DigitalAssetTemplates that govern the behaviour of each contract type. For example, there could be a Single-use Token template for simple ticketing systems, a Coupon template for loyalty programmes, and so on.
  • The template system is intended to be highly flexible and additional templates can be added to the protocol periodically.
  • Asset issuers can link a Registered Asset Issuer Domain (RAID) ID in an OpenAlias TXT public Domain Name System (DNS) record to a Fully Qualified Domain Name (FQDN) that they own. This is to help disambiguate similar contracts and improve the signal-to-noise ratio from scam or copycat contracts.

An AI will issue a DA by constructing a contract from one of the supported set of DigitalAssetTemplates. The AI will choose how large the committee of VNs will be for this DA, and have the option to nominate Trusted Nodes to be part of the VN committee for the DA. Any remaining spots on the committee will be filled by permissionless VNs that are selected according to a CommitteeSelectionStrategy. This is a strategy that an AI will use to select from the set of potential candidate VNs that nominated themselves for a position on the committee when the AI broadcast a public call for VNs during the asset creation process. For the VNs to accept the appointment to the committee, they will need to put up the specified collateral.