Biosample Permission Token with Non-Fungible Tokens

A new model for tracking permissions using established blockchain standards, and an application for biosample data, is introduced.

Written by: William Entriken, Daniel Uribe.

The permission problem space

Permission is a broad problem space covering any permit, where a permitter will ultimately authorize some property use to a permittee. These permits cover a broad field of authorizations, which may also be called “grants,” “consents,” “licenses,” and “clams.” A practical example is the licensing deals in force to produce FIFA 20, a football video game [EA-1] [EA-2] [FIFA-1]:

In the classical example above, every permit shown is individually negotiated and signed between a permitter and permittee. These agreements are signed, bound under the laws of a specific jurisdiction and made between two legal entities.

This paper introduces a new business model where a permitee can accept and use property from a permitter without directly having a contract.

In this paper, we use the following terminology to define permission participants:

  • Biosample permission platform, “platform” — a business intermediary to support permission participants

  • Property — any intellectual or physical property interest, right or endorsement which can be granted

  • Permitter — a legal entity which can authorize use of property

    • A A permitter must be able to create, activate and revoke grants using the platform.
    • B A permitter must be able to restrict derivative permits (i.e. sublicenses) of any of its permits using the platform.
  • Permitee — a legal entity which desires to receive permission on property

    • C A permitee must confirm that any permit they receive is from a permitter that actually is authorized to make such a permit.
    • D The permitee identity must be public. This allows the owner to take action against any unauthorized use.
  • Permit — a permission on a specific property, granted from an authorized permiter to a beneficiary permitee

    • E The public must see the current status of any permit. This allows proper auditing.
  • Owner — the legal entity for any given property which enjoys the exclusive original right to permit usage on it

We will introduce below a general system using established blockchain standards to support the classic business case above as well as a new business model more focused on privacy.

A basic biosample permission platform

We put forth a basic system for a permission platform to publish information and represent any permission relationship.

Data inside the permission platform

This diagram below illustrates which data is required to keep inside this system:

This published permit information includes the status of whether the license is active or revoked (E).

Permit references outside the platform

The identity of the permitee must be public (D), this is how the media owner and the permitee’s customers can verify the authenticity of any permit.

The permitee does this by simply using their existing well-known publishing channel (press release, etc.) to make a statement that this legal entity supports the permission platform and show their identifier.

Owner references

In the same way that the public needs to verify the status of every permit, the permitee needs to verify that any permit they are relying on is authorized. If you are buying the Brooklyn Bridge, make sure the seller is the New York City Department of Transportation [NYCDOT-1]! The platform achieves this by:

  1. Validating the owner identity & media authorization and indemnifying the permitee; and/or
  2. The owner/donor of a biosample self-identifies pseudonymously directly at the time of sample collection

This allows the platform to provide assurance to a permitee that permit they receive is from a permitter that actually is authorized to make such a permit (C).

Using non-fungible tokens to create and look up permits

To implement the basic permission platform above using a blockchain system, it is necessary to implement three features:

  1. The platform will assign identities pseudonymously to owners and publicly to permitees using public-key cryptography.
  2. The platform will assign property identifiers to owners after verifying ownership/authorization.
  3. Anybody can become a permittor by creating any permit of any property to any permitee.

Because this is a blockchain system, all read-only operations are assumed to be free:

  1. Anybody can find the pseudonymous identity of the owner of property.
  2. Anybody can check the current status of any permit, recursively, back to the property owner.

There are several potential approaches to create a blockchain system implementing these required features, we have chosen ERC-721 non-fungible tokens because this is a finalized standard [ERC-721] in production use. We adopt the reference implementation of ERC-721, including ERC721Metadata [0XCERT-1], use a special scheme for token identifiers and add two specialized functions.

Token identifier layout

Every token represents a permit or an identity. And identities are only valid if issued by the permission platform. On Ethereum Virtual Machine blockchains, the word length (and token IDs) are 256 bits and public keys are 160 bits [ETHEREUM-1]. Token identifiers (“IDs”) use a special layout to reference all details needed for a license or identity, shown below:

FieldLength
Permitter public key160 bits
Property registered identifier48 bits
Permitee registered identifier48 bits
Total256 bits

where registered identifiers are explained following.

Convention on registering identity tokens

The platform will be responsible for identifying and authorizing all owners and permittees on the system. The platform does this using a convention.

The platform administrative blockchain account will be a well-known public address (e.g. published on the platform’s website and published with press releases). This administrative account will create identity tokens in the following way:

  • Permitter public key := the platform administrative blockchain account
  • Property registered identifier := 0 (this indicates no property)
  • Recipient (owner or permittee) registered identifier =: registered identifier (id1, id2, id3, …)

There can be no duplicate tokens in ERC-721 sharing the same token ID. The platform administrative blockchain account will create this identity token and transfer the token to the account that will control that identity ID. Therefore the recipient should wait to confirm that the platform recognizes them before using that account. After transferring this token, it shall be impossible for the platform administrative blockchain account to recreate or reassign that registered identifier, and anybody shall be able to find the owner of that registered identifier.

Convention on registering property tokens

The platform will be responsible for registering property identifiers. The platform does this using a convention.

The platform administrative blockchain account will be a well-known public address (e.g. published on the platform’s website and published with press releases). This administrative account will create property tokens in the following way:

  • License public key = the platform administrative blockchain account
  • Property registered identifier = registered identifier (m1, m2, m3, …)
  • Licensor registered identifier = 0 (this indicates no licensor)

There can be no duplicate tokens in ERC-721 sharing the same token ID. The platform administrative blockchain account will create this media token and transfer the token to the account that is the owner for that media identifier. Therefore the owner should wait to confirm that the platform recognizes them before creating any permit with it.

Specialized minting function

This minting function is an extension to ERC-721 which uses the token identifier layout above and allows anybody to mint tokens only when they are namespaced under that minter’s public key.

/**
 * @dev Mints a new NFT.
 * @param _to The address that will own the minted NFT.
 * @param _tokenId of the NFT to be minted by the msg.sender.
 * @param _uri String representing RFC 3986 URI.
 */
function mint(
  uint256 _tokenId,
  string calldata _permission
)
  external
{
  require(address(_tokenId) == msg.sender, "TokenIds are namespaced to licensees");
  NFToken._mint(msg.sender, _tokenId);
  NFTokenMetadata._setTokenUri(_tokenId, _permission);
  emit URI(_permission, _tokenId);
}

Specialized metadata function

Likewise, this metadata function is a similar extension to ERC721Metadata which allows anybody to set metadata for tokens they could mint (A, B).

/**
 * @dev Set a permission for a given NFT ID.
 * @param _tokenId Id for which we want URI.
 * @param _uri String representing RFC 3986 URI.
 */
function setTokenUri(
  uint256 _tokenId,
  string calldata _uri
)
  external
{
  address tokenOwner = idToOwner[_tokenId];
  require(tokenOwner == msg.sender, NOT_OWNER);
  NFTokenMetadata._setTokenUri(_tokenId, _uri);
  emit URI(_uri, _tokenId); // This is a convenience event to help find permission changes
}

Metadata will be stored using a Uniform Resource Identifier for simple permits [] such as data:active and data:revoked to represent active and revoked license states. More complicated licenses can use Universe Resource Names or other links to persistent documents. Those documents could be encrypted as needed.

Other relevant standardization efforts

Other projects have been started to study and standardize claims or authorizations using an Ethereum Virtual Machine blockchain. These include ERC-735 (DRAFT), ERC-780 (DRAFT), ERC-1812 (DRAFT) and possibly more. One commercial product has published on using blockchain for licensing intellectual property [BLMP-1].

The role of permission platform, the role of blockchain

Of course, the classical permission business model is well known and has been in practice for hundreds of years [MS-1]. By adding a permission platform and blockchain, several distinct advantages are derived.

The blockchain allows:

  1. Owners have strict privacy guarantees — they provide zero personal information to anybody.
  2. Owners and intermediary permitters can revoke any permit using the public blockchain network, even without the cooperation of the permission platform or permitees.

The permission platform allows:

  1. Permitees can verify status of a permit across multiple jurisdictions and multiple intermediaries.
  2. Owners can hope the permission platform will represent their interest in auditing permitees’ proper use of property.

Application to biometric data and genomics

As a father, and a cybersecurity expert, Daniel wants to use this new amazing technology to make sure that his own son, when he becomes an adult, has proof that Daniel used the best technology available to protect his son’s privacy. Because this is about his DNA and the DNA of the whole family. This is the opportunity to change the status quo to change of who is in charge of the data and give people self-sovereignty over their data.

Thanks to amazing advances in science, now we have $100 whole-genome sequencing on the market. We also have a portable DNA sequencer for less than the cost of an iPhone. So we are literally on the brink of using our DNA for multiple applications because it is now affordable. This includes medical research, personalized nutrition, forensics (human identification), personalized medicine, etc. The main issue is going to be the proper and ethical management of this data. According to a KPMG study, the main disincentive to participate in these studies is currently privacy.

65% of individuals willing to use an at-home [Direct-to-Consumer Genetic Test] service reported privacy as one of the main concerns; specifically, the potential sharing of data with third parties including consumer health, pharmaceutical, and insurance companies. Almost all of the respondents willing to use the service had concerns about a company owning their DNA profile. [KPMG-1]

The world already has privacy laws like the General Data Protection Regulation (GDPR) and California Consumer Privacy Act (CCPA), but it is very difficult for biosample donors to exercise their rights or make a claim using these regulations because there is lack of traceability and proof when an entity misuses biosamples or data. This is an opportunity for custodians of biosamples to provide proof to their customers that they are handling samples only as expected. This will provide a differentiator for companies that provide and traceability over other companies that use broad-consent forms that “can be updated at any time” which customers do not trust.

With this new token, we are hoping to contribute to everybody that places their trust into health care systems. Companies can become more responsible and ethical where they manage human data and biosamples. Let’s do our part to improve the system, so that donors can better trust health care and be more comfortable to participate in studies, so researchers can have more access to data, which gives doctors more access to life-saving innovations.

Future research

Some items discussed in this paper are areas for future research:

  1. Legal applicability of promissory estoppel or similar legal theory to allow anonymous owners of property to make claims against permitees
  2. Implementing the permission platform into a user-friendly product

References

The permission problem space

A basic biosample permission platform

Using non-fungible tokens to create and look up permits

The role of permission platform, the role of blockchain

Application to biometric data and genomics

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