Making Cryptographs Eternal

How Crypograph’s Renatus safeguard prevents NFT burning in a decentralised way

Creating Digital Legacies

The notion of perpetuity is of great importance to us at Cryptograph. It is even reflected in the name of our company, Perpetual Altruism. We see Cryptographs as a digital legacy of their creator, meant to raise money for a cause close to their heart and for their estate even after their death. The decentralised nature of the blockchain allows for digital assets to withstand time like a block of marble. It is the technological foundation of Cryptograph.

Although the blockchain guarantees an unbreakable registry of ownership using public-private key cryptography (think of it as a login and a very complex unique password that cannot be changed), this also means that digital assets can be forever lost if that private key (the password) is lost. If the private key of a wallet address is irretrievably lost, or if the digital asset is sent to a public address of which there is no known private key (a practice called “burning”), the asset cannot be recovered. The chance of randomly guessing a wallet address’s private key is 1 in 2^160.

What I imagine when people tell me they are burning tokens on the blockchain

Permanently losing access to digital assets can be intentional (like crypto exchange Binance burning BNB tokens) or accidental: In July 2016, someone tragically sent their crypto life savings of 1,493 ETH to the Ethereum genesis address. In the case of a Non-Fungible Token (“NFT”) like a Cryptograph, this would mean the irreplicable loss of art, something that cannot be bought back. A lost Cryptograph would prevent it from carrying out its purpose of raising money for its creator’s charitable cause and preserve its legacy. As NFTs become ubiquitous over the next decade, the need for an on-chain way to safeguard against NFT being lost forever has arisen. The next Mona Lisa may well be a digital collectible, and we better make sure it is not accidentally lost.

Renatus: Trustless NFT Safeguard

Cryptographs are digital legacies. As a Cryptograph owner, you hold the NFT and reap the benefits of ownership, but you are more than just its owner. You are responsible for preserving it so that it can continue to carry out its purpose. You are a Cryptograph patron.

In order to ensure that they will never be irretrievably lost and will perpetually carry on their purpose, Cryptographs have a built-in safeguard function called renatus().

The renatus function is only aimed at preventing accidents and vandalism and to ensure legacies are not destroyed. It is built in such a fashion that it cannot be abused, and operates in a trustless manner so that it works even if Perpetual Altruism were to disappear. In short, if for unfortunate reasons a Cryptograph were to become lost, after five years and under certain conditions it will be able to put itself back on the market and the Cryptograph will be able to carry out its purpose again.

The renatus function works as follows:

1. The renatus function has an on-chain timer that records how much time has elapsed since the last interaction of a Cryptograph owner (or its ERC-721 operators) with that Cryptograph. The timer is automatically reset for that Cryptograph every time the owner or an ERC-721 operator of the token interacts with it in any way, or when the Cryptograph changes hands. The owner can also reset the timer at any time by simply calling the renatus function of the Cryptograph him/herself (for a small gas amount comparable to the cost of a standard money transfer).
2. If a Cryptograph owner (or its ERC-721 operators) has not interacted in any way with their Cryptograph for over 5 years, then anyone can now call the renatus function.
3. When renatus() is called by someone other than the Cryptograph owner (or its ERC-721 operators), a 1-month grace period starts. The owner can still reset the timer at any point during that time by calling the Renatus function.
4. Just like the owner, Perpetual Altruism also has the ability to call Renatus during the grace period to extend the timer. As a policy, if the owner has forgotten to reset the timer but Perpetual Altruism finds any sign of activity of the wallet on or off-chain, we will of course intervene to reset the timer. However, if the Cryptograph token was sent to a known “ burn address” like 0xdeaddeaddeaddeaddeaddeaddeaddeaddeaddead for example, Perpetual Altruism will not intervene and let the process run its course.
5. If at the end of the grace period, after more than 5 years and 1 month of no activity and without a reset by either the owner or Perpetual Altruism, Renatus can be called again by anyone. When called, the Cryptograph will automatically go under auction after 14 days with the previous highest offer as the starting bid. The proceeds of that auction will be split between the creator and the charity only.

This process ensures that no one apart from the creator and the charity could directly benefit from renatus() being called. More importantly, it makes the Cryptograph token holder more than just an owner: a patron.