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History and Purpose of the Open Credentialing Initiative (OCI)

The OCI was formed by a group of industry service providers, manufacturers, wholesalers, and dispensers working together to design and deliver an electronic solution for the pharmaceutical industry to achieve compliance with FDA mandates for supply chain security. Upon successful demonstration of the technical solution, and acceptance by the participating manufacturers and wholesalers, the participants formed the OCI to further develop the solution into a set of tools that could be adopted and implemented across the industry.

The name OCI was chosen for the following reasons:

OCI aims to enable pharmaceutical industry compliance with US Drug Supply Chain Security Act (DSCSA) requirements for Authorized Trading Partners (ATP). Beyond supporting the adoption and standardization of the ATP architecture, OCI establishes a structure for running further credential-based pilots and incubation projects. For additional information, please refer to the Open Credentialing Initiative website.

Regulatory Compliance – Federal Mandates

The DSCSA has the objective of securing pharmaceutical drug distribution, from manufacturers all the way to patients. For patient safety, it is essential to know that only trusted and authorized entities are involved in the manufacture, distribution, and dispensing of prescription drugs. In addition to verification, product tracing, and serialization requirements, each supply chain actor must ensure that their Trading Partners are authorized (including indirect Trading Partners).

DSCSA requires that Trading Partners of manufacturers, wholesale distributors, dispensers, and repackagers meet the applicable requirements for being “authorized trading partners” (see sections 582(b)(3), (c )(3), (d)(3), and (e)(3) of the FD&C Act (21 U.S.C. 360eee-1); where “authorized” means registration in accordance with section 510 (manufacturers and repackagers), or having a valid license under State law (wholesalers and dispensers).

Digital Ecosystems - Identity of Transacting Entities

Verifying that a company is “authorized” is enough to meet the letter of the law. However, in digital ecosystems it is also necessary to establish the identity of the company. Thus, it becomes a two part process – is the counterparty who they say they are, and if so, are they “authorized”? To add to this challenge, DSCSA transactions for Product Identifier (PI) Verification and Transaction Information (TI) Tracing move through any number of intermediaries (solution providers, routing systems, etc.), all of whom fall under the Statute. In a digital ecosystem good design is to limit the opportunity for information leaks, transaction replays, and tampering with the transaction or credential content throughout the ecosystem.

Use Case: PI Verification in Salable Returns


Per DSCSA as of November 2019, wholesale distributors are required to verify the product-level serial number on salable returns before selling the product back into the supply chain. The manufacturer must make the serial numbers available for verification. It is estimated that 2 to 4% of pharmaceutical products sold in the US are returned to the wholesale distributors and are eligible to be sold back into the supply chain upon verification.

Due to this high volume, an industry-wide PI verification system was implemented to allow wholesalers to perform the verification. The existing PI verification system allows the exchange of messages between Wholesalers and Manufacturers via various Verification Router Service (VRS) providers as the primary method for automatic verification of so-called serialized Global Trade Item Numbers (sGTIN). This message exchange is to be completed in less than one second. The sGTIN is embedded in a GS1 2D DataMatrix and encodes the following data objects: GTIN, Expiration Date, Batch Number, and Serial Number (S/N). Response times in real-world systems are up to 2 seconds.

VRS are cloud-based, multi-tenant solutions that are integrated with the systems of wholesale distributors (WHO) and manufacturers (MAN). To allow a seamless exchange of PI verification messages between WHO, MAN, and VRS providers, the industry adopted the GS1 Lightweight Messaging Standard as a communication protocol.

When a salable return arrives at the warehouse of a wholesaler, the 2D DataMatrix of each individual package needs to be scanned. After scanning, the Wholesaler sends a PI verification request (VR) to their VRS provider. The VRS then determines a routing path by looking up a service endpoint URL and forwarding the PI request using a Look-up Table and Routing Service Network (e.g. MediLedger) to the Manufacturer’s VRS provider. The Manufacturer VRS queries PI data within the Manufacturer system and then sends a PI verification request response (VR/R) back to the wholesale distributor.

The Look-up Table and Routing Service Network store and maintain look-up data for mapping any sGTIN to the service endpoint of the relevant MANs.

vrs architecture overview

Challenges of the current VRS architecture

In the current system the Global Location Number (GLN) is used to identify trading partners. However, it is not unheard of that a used GLN is either not or incorrectly registered for a trading entity. Additionally, there is no verifiable proof that the provided GLN actually stems from the requesting or responding trading partner.

Hence, existing PI Verification solutions do not fulfill all DSCSA requirements.

The OCI recognizes that:

Digital Wallets describe software that enables trading partners and credential issuers to acquire, store, and present VCs and to manage DIDs. The Digital Wallet provider needs to expose Application Programming Interfaces (APIs) for VRS providers to integrate the credentialing mechanism into PI verifications. Additionally, Digital Wallets of trading partners need to interact with Credential Issuers’ wallets for credential acquisition.

To exchange the ATP credential status between requesters and responders, the OCI uses the header of PI Messages defined by GS1 Lightweight Messaging Standard for Verification of Product Identifiers. The presentation of the ATP credential can be embedded as JSON Web Token (JWT) into a custom header of GS1 lightweight messages without changing the VR and VR/R payload bodies’ data structure.

vrs architecture with credentials


System overview

The diagram below depicts how Digital Wallets are integrated with OCI participants, such as VRS systems and credential issuers. Trading partners have no technical integration effort. All they need to do is to sign up with an OCI-conformant provider and run through the OCI-conformant enterprise identity verification process.

OCI architecture with credentials

Credential acquisition

In the OCI architecture, trading partners can manage their credentials themselves. While gathering information about a company’s ATP status is relatively simple, ensuring that an ATP credential is being granted to the right entity, and not an imposter, is more challenging. By performing thorough and auditable due diligence, a Credential Issuer promotes confidence in a Trading Partner’s digital identity prior to the issuance of an ATP credential. The Identity Credential becomes the Root of Trust upon which an ATP credential can be issued.

OCI ATP issuance process

Enterprise Identity Verification

Prior to credential issuance, a trading partner’s enterprise identifier (DID) needs to be verified through an identity verification process. Enterprise identity verification is completed by the Credential Issuer according to OCI-defined conformance criteria for Credential Issuers. Upon successful verification, the Credential Issuer will release an identity credential that is used as the Root of Trust within the ecosystem. In addition, the Credential Issuer will perform due diligence on the license status of the trading partner and issue an ATP credential if appropriate.

For management of credentials, the digital wallet provider shall provide to the trading partner a web user interface (application layer).

Credentialized PI verification flow

The OCI-conformant digital wallet providers need to furnish the VRS providers with APIs to:

  1. Generate a Verifiable Presentation of a DSCSA ATP Credential in form of a JWT
  2. Verify a Verifiable Presentation of a DSCSA ATP Credential

The diagrams below depict how digital wallets for credential management are integrated into the existing PI verification systems utilized by VRS providers.

PI verification flow

Generating a Verifiable Presentation of the DSCSA ATP Credential in form of a JWT

GS1 provides a standardized Lightweight Verification Message format that can be easily implemented by all VRS providers. The required verifiable credential presentation can be added in the form of a JWT to the message header, leaving the message body unchanged.

The VRS calls the Wallet APIs by providing the CorrUUID, DID and the required credential type. The response is a JWT including the Verifiable Presentation of the DSCSA ATP Credential. The JWT is attached to the VR message header. The VRS can do this for any of their customers using a digital wallet holding credentials.

The PI request process is depicted in the figure below:

Generating a Verifiable Presentation

For recurring requests to create a verifiable presentation, the DID resolution and the revocation check of the ATP credential can be cached in memory so that the API latency will be reduced to just the time required to sign a verifiable credential and associated hash.

The VRS then routes the Verification Request (or Response) to the other VRS where the credentials are verified. If the credentials are correct, the message will be accepted. Otherwise, an error will be created, and the request or response will not be accepted. The VRS uses the API to verify a received verifiable presentation.

Verification of Verifiable Presentations of DSCSA ATP Credentials

The verification flow starts with the VRS sending the JWT and the verifier DID to the Digital Wallet of the trading partner receiving either a PI request or response message:

Verifying a Verifiable Presentation

The charts above depict the verification process. According to DSCSA, both requesters and responders must also check the ATP status of the trading partner sending the PI verification request or response.

OCI system architecture overview

OCI system architecture overview

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© 2022 Open Credentialing Initiative

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

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