A digital badge on a profile looks like a small image. Under the current version of the Open Badges standard, the image is the least important part. Open Badges 3.0, maintained by the education technology standards body 1EdTech, makes every badge a signed data file built on the World Wide Web Consortium's Verifiable Credentials data model. That changes what a badge carries and how an employer, a registrar or a licensing office can check one.

What changed from version 2.0

In 3.0, every badge award is also a verifiable credential. The specification's schemas follow version 2.0 of the W3C Verifiable Credentials Data Model, though issuers may use schemas compatible with version 1.1, and verifiers may accept either.

The vocabulary changed with it. What version 2.0 called an Assertion is now an OpenBadgeCredential, and what it called a BadgeClass is now an Achievement. The implementation guide also describes a shift in how trust works. Under 2.0, a verifier could infer that a badge belonged to an issuer by matching the web domains where the badge data was hosted. Under 3.0, issuers do not have to use web addresses as identifiers, and verification rests mainly on checking the credential's cryptographic proof.

What is inside a badge

An OpenBadgeCredential names the issuer, the person who earned it and the achievement. The Achievement describes what was earned:

  • a name and description, and an achievement type such as a competency;
  • criteria, written as a narrative of what the earner had to do;
  • the creator, the organization that defined the achievement;
  • optional fields for an image, tags and a version.

An achievement can also carry alignments, which point to an entry in an outside framework. Each alignment records the framework, the code and name of the item, a link to it and its type. The types listed in the implementation guide include items published in the CASE format for academic standards and credentials and competencies described in the Credential Transparency Description Language, the vocabulary behind the national credential registry. An alignment is how a badge can say that it maps to a named skill in a framework someone else maintains.

The credential can also hold the date of the achievement, an expiration date, results and evidence.

Who the badge belongs to

A badge has to identify its earner without exposing more than necessary. The specification allows two approaches. The earner can be identified by a decentralized identifier, once they have shown they control it. Or the badge can carry an identity object with a hashed and salted value, such as an email address, so the earner can prove the badge is theirs by supplying the original value while a casual reader of the file cannot see it.

How a verifier checks one

The specification defines verification in three parts: the credential must conform to the standard, its proof must check out, and any status check must succeed.

The proof is a digital signature in one of two formats, a JSON Web Token or a Data Integrity proof. The signature points to a public key that must appear in the issuer's profile. The issuer itself can be identified by an ordinary web address or by a decentralized identifier, and either one resolves to that profile and its key. If anything in the badge was altered after signing, the check fails.

Status covers revocation. A badge can name a status entry that the issuer updates if the award is withdrawn. The implementation guide recommends the W3C Bitstring Status List, in which one published list holds the status of many credentials at once. A verifier downloads the list and reads one position in it, so the issuer cannot tell which credential was being checked.

The implementation guide adds a limit worth knowing: digital wallets may check only part of the validity rules, so a wallet showing a badge is not the same as a full verification.

Badges, learner records and endorsements

1EdTech publishes a companion standard, the Comprehensive Learner Record 2.0, which uses the same signing approach. A badge carries an image in PNG or SVG format. A learner record carries no image and instead bundles many achievement credentials into one longitudinal record, closer to a transcript. Endorsements, in which a third party vouches for an issuer or an achievement, are signed the same way as the badges themselves.

What a valid badge does and does not prove

A badge that passes verification shows who issued it, to whom, for which defined achievement, that it has not been altered and that the issuer has not revoked it. It does not, by itself, say how the earner was assessed. That information lives in the criteria, the evidence and any alignment, and it is only as detailed as the issuer chose to make it.

For an employer or registrar, the practical sequence is to ask for the credential file rather than a screenshot, run it through a verifier that supports version 3.0, and then read the criteria, evidence and alignments to decide what the achievement represents. For an issuer, 1EdTech publishes conformance and certification guides for versions 2.0, 2.1 and 3.0.

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