Since the introduction of Verifiable Credentials, there has been a Cambrian explosion in the number and variety of use cases. This is depicted in the illustration below.
Cambrian explosion of certificate types
Let's look at some of the specific use cases. Please note that all of these examples are credentials conferred by some issuer and are not forms of identification.
- Academic and Award Certificates - These are the most common use case for verifiable credentials. The certificate can contain basic information about an attainment, such as a diploma or a degree, or it can contain a complete transcript. Unfortunately, there are as yet no standards for exchange of transcript data between institutions, so most implementations today are simple award certificates. This is the most common type of certificate, used for event certificates of participation and continuing education.
- Sporting Achievements - The use of certificates for sporting achievements is an obvious application. Verifiable Credentials would be welcomed in sports such as Taekwondo, in which coaches keep detailed records of achievements and the results of competitions, usually in paper booklets. Sporting achievements can be memorialised in trophies or medals that are laser-etched with a QR code which is linked to the verifiable digital certificate.
- Health Status - Verifiable digital certificates were widely used in the pandemic to prove that individuals had passed screening tests or had been vaccinated against Covid. Although many vendors offered competing implementations, almost all were based on the W3C Verifiable Credentials data format with medical information expressed in Fast Healthcare Interoperability Resources (FHIR) codes. Adoption was mandated and was in fact the first VC used by the millions who travelled during the pandemic.
- Personal Medical Records - This is one of the most compelling use cases for VCs because it enables individuals to present their basic health information to physicians or health service providers wherever they may be. For example, Personal Medical Records (PMRs) are useful to travelling athletic teams. Health Insurance and Benefits Providers use PMRs to encourage healthy lifestyles and early detection of medical issues.
- Certificates Of Authenticity - A Certificate of Authenticity (COA) is relevant for digital works of art, since the files are easily copied and authorship can be disputed. Each COA includes an image hash, thumbnail, artist's signature and other attributes that are tied to a specific high-resolution image. With this hash, a buyer or other relying party can determine the identify the copyright owner and that the image (and authorised copies) are authentic. This is a solution to the misrepresentation and fraud which is rife in the NFT market.
- Document Integrity - A QR code overlaid onto a document can be linked to an attestation that it hasn't been tampered with. There are great uses cases here, such as when official documents need to be protected from forgery or when engineering drawings are relied on long after the engineers have gone. To verify document integrity, the user simply scans the QR code and uploads the document for verification. The QR image signals: 'trust buy verify'.
- Carbon Credits - When trees are planted or carbon dioxide is removed from the environment, credits are created that a business can use to offset taxes or emit their own greenhouse gases. To facilitate a spot market in carbon credits, issuance can be done using a Verifiable Credential and this VC is then converted to an NFT. Tokenisation makes the carbon credits tradeable.
- Property Titles - A certificate can represent a property title in digital form. It could be the deed to a piece of real estate, an asset such as gold bars or even a crate of rare whiskey. The certificate might use the same design as the label on the whiskey bottle, but it's not just a fanciful commemorative. It is a digital representation of ownership, recognized in jurisdictions that allow electronic records as evidence. Once the certificate is converted to an NFT, this asset can be fractionalized and the units sold to multiple investors.
Verifiable Credentials have so many compelling use cases. But to exploit all these use cases, without constant re-engineering, one must have a very flexible issuance mechanism. This is discussed in the upcoming chapter on Services.