How provenance is stored on the blockchain

Ever wonder exactly *how* information about art is stored on the blockchain? Take a step by step look into Codex’s provenance section to learn.
Graphic: Anthony A. LoPresti

Last week we released an overhaul to the Codex Viewer to derive substantial search engine optimization (SEO) improvements and increase provenance tracking functionality. You can read last week’s article here that outlines the SEO, speed and design improvements. In this article we’re focusing on the updates in the provenance section.

We’re taking the redesign of the new, robust provenance section on Codex Records as an opportunity to explain exactly how documenting provenance on the blockchain works. By breaking down each component of the provenance section of Codex Records, we can understand why blockchain technology is revolutionary for the arts and collectibles industry.

First, let’s start with the DNA of provenance on Codex. The new provenance section of a Codex Record is comprised of four parts:

  1. Provenance
  2. Record Details
  3. Hash Verification
  4. Additional Files

By looking at each of those four sections we can illustrate how they work and why they are important.

Part 1: the Provenance tab

This first tab lists every blockchain transaction associated with the Codex Record, depicting its “blockchain history.” These transactions include creation, modifications and transfers, as shown below in image 1.

Image 1

By clicking on a transaction, the viewer can see more details of that blockchain action (image 2), such as “edited” or “transferred” — normal components of the provenance of a collectible item. Let’s break down each of those details next.

Image 2
  • Transaction hash —every action that modifies information about a Codex Record (i.e. Create, Modify, or Transfer) will generate a transaction on the Ethereum blockchain. All transactions sent to the Ethereum blockchain are assigned a unique identifier via a cryptographic algorithm called a “transaction hash.” As all changes are recorded via transactions, a Codex Record’s transactions are essentially its digital provenance. A new hash is generated anytime there is a change to the data in the Codex Record. Thus creating an immutable, record keeping ledger.
  • Etherscan Link — every transaction hash is accompanied by an Etherscan link. Etherscan shows details of every transaction mined on the Ethereum blockchain. By clicking the Etherscan link on a Codex Record, the viewer has access to all details about that action (image 3), such as a Record transfer or modification. This allows viewers to verify transactions independently of Codex.
image 3 — Etherscan link
  • Changes — Metadata that can be changed on a Codex Record include name, description, main image, additional images and additional files. If anything on a Record is modified, it will be reflected in the provenance section. Refer to image 2 above, the owner of the Record can see all pre-modified text in red as and modified text in green. The original text is private and can only be viewed by the owner.  Viewers of the Record only see a “yes” or “no” beside the “Changed” information sections. However, the owner of the Record can grant anyone view-only access to the Record, allowing them to view the edit history and see what the original content was before the changes were made.

Note: The owner of a Codex Record (NFT) has the power to amend any of the metadata on the Record; this is a part of the nature of NFTs. This can be a concern for digital artists who worry someone will buy their work and alter it. This new “tracking changes” features aims to mitigate that as anyone who owns or views the Record will see who made any modifications and what the content was before it was modified.

Part 2: Record Details

“Record Details” are the general settings of a Codex Record. This is mostly off-chain data that is stored in the Codex database. There are a couple important details here. The first: the wallet address or name (if the user is Verified) of the creator of the Record will always be displayed in the Record Details. As an artwork or collectible items changes hands, there will always be easy access to see who was the original creator of the digital blockchain Record.

Secondly, it’s important to note that to enable privacy controls, metadata must be hosted off-chain in a traditional database; the only information stored on the blockchain are the hashes of the metadata. This means any changes to the Codex Record will reflect in a new hash [that is stored on the blockchain], while the data itself is stored on any chosen metadata provider.

Part 3: Hash Verification

The hash verification section shows the latest hash values for the Record’s name, description and any additional photos and files.

As explained in part 1, any time there is a change to data in a Codex Record, a new hash is formulated. The Hash Verification section of the Codex Record displays the most up to date hash of the three components of a Codex Record.

The hash function (the cryptographic algorithm that creates the hash ID) runs in your browser and hashes the plain text values and compares them to what is stored on the blockchain — if it matches, it will show the green checkmark badge beside the hash, as depicted in the image above. This allows you to verify that the hash you are looking at has not been tampered.


Blockchain is commonly referred to as a ledger, and when it’s used to track provenance of an artwork or collectible item it’s a brilliant way to ensure immutability and transparency. Every time anything on a Record is modified a new hash is generated, leaving an immutable trail of events. Hashes are the secret weapon to provenance on the blockchain. It allows one to keep their data private while simultaneously proving to the world its validity.

Written by: Corinne Moshy


About Codex

Codex is the leading decentralized asset registry for the $2 trillion arts & collectibles (“A&C”) ecosystem, which includes art, fine wine, collectible cars, antiques, decorative arts, coins, watches, jewelry, and more. Powered by the CodexCoin native token, the Codex Protocol is open source, allowing third-party players in the A&C ecosystem to build applications and utilize the title system. Codex’s landmark application, Biddable, is a title-escrow system built on the Codex Protocol, which solves long-standing challenges in auctions: non-performing bidders, lack of privacy and bidder access. The Codex Protocol and CodexCoin will be adopted as the only cryptocurrency by The Codex Consortium, a group of major stakeholders in the A&C space who facilitate over $6 Billion in sales to millions of bidders across tens of thousands of auctions from 5,000 auction houses in over 50 countries.

To learn more about Codex initiatives, visit our white paper. To inquire about partnerships and developing dApps using the Codex Protocol, please contact us via Telegram or Twitter