Soulbound Tokens (SBTs) for Digital Certifications and Badges

Pain

Your organization hands out thousands of professional certifications and internal compliance badges--think HIPAA, PCI DSS, secure coding, and safety training. But here’s the thing:

• Revocation is a hassle: If someone switches jobs or wallets, their “badge” can’t be rotated without going through a bunch of manual exceptions.
• Audit evidence takes ages: Just grabbing screenshots or LMS exports won’t cut it for SOC 2/ISO 27001 auditors. They need a solid, verifiable trail.
• Vendor lock-in is real: These proprietary badge platforms don’t play well with enterprise SSO, eIDAS wallets, or commonly used HRIS like Workday, SAP, and Oracle.
• Privacy pitfalls: Keeping PII on-chain raises GDPR/FERPA concerns, but relying solely on off-chain links can lack integrity, making verifiers hesitant to trust them.

Right now, the standards that your auditors and procurement teams are looking for are already set in stone and a bit outdated:

• W3C Verifiable Credentials Data Model 2.0 got the thumbs up as a W3C Recommendation on May 15, 2025.
• OpenID for Verifiable Credential Issuance 1.0 reached Final Specification status in 2025, and self‑certification kicked off in February 2026.
• NIST SP 800‑63‑4, which wrapped up in July 2025, clearly acknowledges subscriber‑controlled wallets in federation models.

For more details, check out the official reference: (w3.org).

Agitation

If you overlook these shifts, you’re definitely going to notice some tough outcomes:

• Missed renewal deadlines: The EU's eIDAS 2.0 is making a big push here--by 2026, every Member State needs to roll out certified European Digital Identity Wallets (EUDI). So, be ready! Your verifiers, like universities and regulators, are going to expect wallet-native credentials instead of the old-school PDFs or proprietary badge URLs. Check out more details here.
• Failed RFPs: These days, RFPs and third-party risk teams are getting serious--they’re looking for W3C VC 2.0, OIDC4VCI/4VP, and revocation through Bitstring Status Lists. These are essential check-the-box items that you definitely can’t fake. If you want to dive deeper, take a look here.
• Audit exposure: According to NIST 800-63-4 and the latest privacy guidelines, handing out credentials without selective disclosure (SD-JWT/BBS+) or revocation telemetry is a big no-no; it raises a lot of concerns. Don't get caught off guard--fines and the need for remediation can wipe out any savings you might get from those “quick win” badge vendors. More info can be found here.
• L2 economics are here; your ops aren’t: with the recent Dencun upgrade, L2 fees have plummeted, making it super affordable to do verifiable issuance at scale. But here’s the catch: you need to make sure your contracts and issuance pipelines are all set up for ERC-1155 batching and rollup fee markets (think Base’s minimum base fee policy). Otherwise, those "gas-optimized" decks could end up costing you more than you bargained for! For more insights, check this out here.

Bottom line: every quarter you wait adds to verification costs, stretches out audit cycles, and gives up procurement power to those one-off solutions that definitely won’t make the cut when it comes to next year’s interoperability tests.

Solution

7Block Labs rolls out a standards-first SBT credential stack that seamlessly integrates into your identity and audit workflows, all while keeping the crypto jargon at bay and steering clear of vendor lock-in.

We’ve got three layers in the mix:

1. On-chain attestation and binding
2. Off-chain credential formats that your auditors will appreciate
3. Privacy-preserving verification processes that integrate smoothly with enterprise SSO and wallets

1) On‑chain: robust, minimal, and revocable SBTs

• Interface choices based on what you need:
  • ERC‑5192 (Minimal Soulbound) is perfect for those “always‑locked” badges. Just a simple locked() check (and it's EIP‑165 discoverable too). This is great for completion badges that you never want to transfer. Check it out here.
  • ERC‑5484 (Consensual SBT) comes in handy when you’re looking for immutable, per‑token burn policies. Whether it’s issuer-burnable, holder-burnable, or a mix of both, this will help you manage key rotation or revoke policies without the hassle of transfers. Learn more about it here.
  • ERC‑5633 (1155 extension) is your go-to when you need to batch-mint different types of certifications at scale, like role matrices. It lets you mix soulbound and transferable IDs in one contract. Dive into the details here.
• Attestation rail: The Ethereum Attestation Service (EAS) is here to securely anchor credential hashes and their statuses while keeping your personal info under wraps. You’ve got schemas that outline your badge fields, resolvers that uphold on-chain rules, and you can link attestations using SBT token IDs for easy revocation and audit trails. Check it out at (easscan.org).
• Wallet/signature compatibility: We’re using EIP‑712 structured data to streamline issuance consent flows, plus we’ve got smart contract wallet compatibility in the mix through EIP‑1271 signature checks when necessary. (eips.ethereum.org)
• Rollup Economics: When it comes to deploying on an L2, we've found that using Base works wonders, especially for enterprise pilots. The perks of Coinbase custody and efficient fiat rails make it a top choice for us. Plus, the documented minimum base fee controls ensure that the usual transaction costs hover around just a few cents, even when ETH prices are moderate. Check it out for more details! (docs.base.org)

2) Off‑chain: W3C VC 2.0 credentials your verifiers can trust

• We provide a W3C Verifiable Credential 2.0 right alongside the SBT, and it’s signed using one of these methods:
  • Data Integrity (Ed25519/ECDSA cryptosuites), or
  • JOSE/COSE (JWT/CBOR) featuring Selective Disclosure JWT (SD‑JWT), which lets you “show only what’s needed” for verifications. Check it out here: (w3.org)
• Privacy-Preserving Presentations:
  • Exciting news! SD-JWT is now an official IETF standard (RFC 9901, Nov 2025). This means that when you receive a presentation, you only have to show the necessary claims, like “cert current” or “role=Senior Engineer,” instead of sharing the whole transcript. You can check it out here.
  • Additionally, BBS+ selective disclosure is making strides towards becoming a standard within W3C’s Data Integrity BBS Cryptosuites. This is great for creating unlinkable proofs in regulated environments. Learn more about it here.
• Revocation/compliance:
  • We’ve got a Bitstring Status List and/or an EAS-backed revocation schema in place, letting verifiers check status right away without needing to hit up your LMS. This approach aligns with VC 2.0 best practices for keeping revocation private. (w3.org)
• LMS/HRIS fit:
  • Open Badges 3.0 is totally in sync with VC 2.0, which means you can enhance your current L&D assets instead of starting from scratch. We also roll out Displayer/Verifier services to ensure everything meets 1EdTech standards. (imsglobal.org)

3) Interop and federation: OIDC‑native for enterprise SSO

• You can now issue and present Verifiable Credentials through OpenID (OIDC4VCI/4VP), meaning your Single Sign-On (SSO) does more than just log you in--it handles verifiable claims too! The spec hit its Final stage in 2025, and self-certification will kick off in February 2026. This is definitely something procurement and InfoSec teams will want to keep on their radar. Check it out here: (openid.net)
• Regulatory alignment: NIST SP 800‑63‑4 (final release set for July 2025) recognizes subscriber-controlled wallets within federation models. Our processes align with AAL/FAL targets and fit right into your privacy risk register. Check it out at (pages.nist.gov).
• EU-readiness: With the upcoming eIDAS 2.0 and EUDI wallet timelines, cross-border verifiers will be looking for wallet-presented credentials by 2026. Our platform provides compatible VCs and is in line with the OpenID conformance profiles being used in EUDI pilots. Check out more details here.

---

Architecture at a glance

• Smart Contracts: We've got ERC‑5192/5484/5633, an EAS schema registry, and some handy policy resolvers.
• Issuer: Think OIDC4VCI issuer combined with a VC signing service (either Data Integrity or SD‑JWT).
• Holder: This could be an Enterprise wallet or an EUDI wallet, featuring an account-abstracted user experience where it makes sense.
• Verifier: We're talking OIDC4VP verifier along with status checkers (yep, that's Bitstring list + EAS).
• Storage: Personal Identifiable Information (PII) is kept off-chain; on-chain, we only store hashes, status bits, and public badge metadata.
• Audit: We maintain append-only issuance logs, along with on-chain events and signed VC issuance receipts for that extra layer of trust.

We provide this through our unique stacks and a bunch of offerings that you might find useful:

• Complete issuance and verification with our web3 development services and smart contract development.
• Strengthening security and compliance with our security audit services.
• HRIS/LMS/IdP connectors available through our blockchain integration.
• Multi-chain badge programs created with our cross-chain solutions development.

---

Example A: University diplomas, HR‑verifiable in under 200 ms

• Diploma issuance: We mint an ERC‑5484 SBT for every graduate, and to keep things flexible, we set burnAuth to Both (meaning either the issuer or the holder can take action). Plus, the tokenURI points to some non-PII metadata. Check it out here: (eip.fun).
• VC 2.0: We're rolling out a “DegreeCredential” (with Data Integrity using Ed25519). This comes with a Bitstring Status List URL, and we’ll store the VC hash in an EAS attestation linked to the tokenId. More details here: (w3.org).
• Verification: When employers want to verify degrees, they can use OIDC4VP to specifically request the info like “degree=BS CS, validUntil>=now.” For selective disclosure, we use SD‑JWT so HR only sees the fields they care about when checking job qualifications. Learn more at: (openid.net).
• Address rotation: If a holder wants to change addresses, they can request a burn-and-reissue through ERC‑5484. We’ll trigger a Burn event, update the Status List, and then re-mint the same badge to the new address, complete with a fresh EAS attestation that references the same VC hash lineage. Details here: (eip.fun).

Example B: Regulated workforce training (HIPAA/PHI‑adjacent), GDPR/FERPA safe

• Contract: We're using the ERC‑5633 multi-type badge contract (think HIPAA‑101 or Security‑Awareness‑2026) with the feature isSoulbound(id)=true. Let’s batch mint these for our cohorts every month. You can check out the details here.
• VC 2.0: Each employee will get one credential that includes status bits for each module. If needed, we can revoke these using the Bitstring Status List. Just a heads-up, we’re not putting any training scores on-chain; we’ll only store module IDs and completion timestamps in the VC. More info is available here.
• Wallets: We’re going with company SSO using OIDC4VP, making sure we stick to NIST 800‑63‑4 for solid authentication assurance. Plus, we’ll time-box presentations for audits to keep everything neat and tidy. You can find the guidelines here.
• Privacy: For proofs showing that someone completed a course within the last 12 months, we’ll use SD‑JWT. This way, we can keep course names under wraps unless it’s absolutely necessary to share them. Get the details here.

Example C: Partner certification program (channel/ISV), global acceptance

• Contracts: We’re using ERC‑5192 minimal SBTs with locked()=true for each certification tier. Plus, you can easily find them thanks to EIP‑165. Check it out here: (eips.ethereum.org)
• Issuance: For issuing, we're leveraging OIDC4VCI right from the partner portal. Our HRIS sync will whip up VCs and mint SBTs on Base, making sub-cent issuance and a clear fee policy a breeze. More details here: (docs.base.org)
• Verification: Distributors can verify using OIDC4VP, and we've got revocation covered through EAS attestations and the Bitstring Status List. This whole setup is compliant with eIDAS 2.0 for wallet acceptance in EU rollouts--pretty neat, right? Get more info here: (easscan.org)

---

Code: minimal, audit‑friendly Solidity

ERC‑5192‑Based SBT with EAS Anchoring

We're rolling out a new approach using ERC‑5192 for Soulbound Tokens (SBTs). This setup includes EAS anchoring along with a consent mechanism through EIP‑712.

To make things more secure, we've strengthened the transfer process. We're also introducing a clear revoke() function that comes with role-based access control and a way to update the EAS status.

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import {ERC721} from "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import {AccessControl} from "@openzeppelin/contracts/access/AccessControl.sol";
import {IERC165} from "@openzeppelin/contracts/utils/introspection/IERC165.sol";

// ERC-5192 minimal soulbound interface
interface IERC5192 is IERC165 {
    event Locked(uint256 tokenId);
    event Unlocked(uint256 tokenId);
    function locked(uint256 tokenId) external view returns (bool);
}

// EAS minimal anchor (interface subset)
interface IEAS {
    function attest(bytes32 schema, bytes calldata data) external returns (bytes32 uid);
    function revoke(bytes32 schema, bytes32 uid, bytes calldata data) external;
}

contract SoulboundCert is ERC721, AccessControl, IERC5192 {
    bytes32 public constant ISSUER_ROLE = keccak256("ISSUER_ROLE");
    IEAS public immutable eas;
    bytes32 public immutable schemaId;

    mapping(uint256 => bool) private _locked;        // always true post-mint
    mapping(uint256 => bytes32) public vcUID;        // EAS attestation UID per token

    constructor(address eas_, bytes32 schema_) ERC721("EnterpriseCert", "ECERT") {
        _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
        _grantRole(ISSUER_ROLE, msg.sender);
        eas = IEAS(eas_);
        schemaId = schema_;
    }

    function supportsInterface(bytes4 iid) public view override(ERC721, AccessControl, IERC165) returns (bool) {
        return iid == type(IERC5192).interfaceId || ERC721.supportsInterface(iid) || AccessControl.supportsInterface(iid);
    }

    function locked(uint256) external pure override returns (bool) {
        return true; // Minimal ERC-5192: always locked after mint
    }

    function issue(address to, uint256 tokenId, bytes calldata vcAnchoredData) external onlyRole(ISSUER_ROLE) {
        _safeMint(to, tokenId);
        _locked[tokenId] = true;
        emit Locked(tokenId);
        vcUID[tokenId] = eas.attest(schemaId, vcAnchoredData); // anchors hash/status pointer
    }

    function revoke(uint256 tokenId, bytes calldata vcRevokeData) external onlyRole(ISSUER_ROLE) {
        bytes32 uid = vcUID[tokenId];
        require(uid != bytes32(0), "No VC UID");
        eas.revoke(schemaId, uid, vcRevokeData);
        // Burn to reflect revocation; re-issue on rotation if needed
        _burn(tokenId);
    }

    // Block transfers per SBT semantics
    function _update(address to, uint256 tokenId, address auth) internal override returns (address) {
        address from = super._update(to, tokenId, auth);
        if (from != address(0) && to != address(0)) revert("SBT: non-transferable");
        return from;
    }
}

Why This Design:

• ERC‑5192 keeps things streamlined for audits. You can check it out here.
• EAS anchoring makes sure that PII is kept separate from the chain state, all while providing auditors with a solid cryptographic trail. More details can be found here.
• Revocation is done explicitly instead of being “soft-deleted,” and you can easily reflect that in your VC Bitstring Status List. Check out this link for more info: w3.org.

---

Implementation playbook (what we actually do in 90 days)

• Week 0-2: Requirements and Risk
  • Start by mapping credentials to VC 2.0 contexts, and don’t forget to classify PII. You'll need to decide on a cryptosuite too: go with SD‑JWT for selective disclosure if that fits your needs, or choose Data Integrity BBS+ if you absolutely need unlinkability. Check out more details here.
  • Next up, you’ll want to define the SBT interface for each credential. Think about whether you need to go with 5192, 5484, or 5633. You can dive into the specifics here.
• Weeks 3-6: Build and Integrate
  • We're diving into smart contracts and EAS schemas, plus making sure everything's secure with our security audit services.
  • Setting up an OIDC4VCI issuer and an OIDC4VP verifier, along with single sign-on (SSO) using your IdP. We’ll also have a solid conformance plan that lines up with OpenID’s self‑cert program kicking off in 2026. Check it out here: (openid.net).
  • We're also working on HRIS/LMS connectors and getting Open Badges 3.0 ready to show off. Want to learn more? Head over to (imsglobal.org).
• Week 7-10: Pilot
  • We'll be rolling out batch issuance on an L2--typically Base--while keeping an eye on fee controls and making sure we meet our gas/throughput SLAs. Check out the details here.
  • For the auditor dry-run, we’ll create evidence packs that include on-chain events, EAS attestations, and VC status lists, all organized according to SOC 2/ISO 27001 controls.
• Week 11-13: Time to toughen up and expand
  • Get into those pen tests, plan for disaster recovery, and set up some “holder rotation” runbooks (think ERC‑5484 burn‑and‑reissue when it makes sense). You can check it out here: (eip.fun).
  • Put together a procurement package that includes architecture, a DPIA (GDPR), data flow diagrams, and those all-important conformance roadmaps.

We’ve got you covered with our awesome custom blockchain development services, top-notch web3 development services, and seamless blockchain integration.

---

Best emerging practices we recommend (and implement)

• Keep personal info off the blockchain. Just store hashes, status, and public metadata on-chain; use VC 2.0 for claims. This way, you’re following GDPR's data minimization principles, plus it makes auditing a breeze. (w3.org)
• Go with ERC‑5484 instead of custom transfer reverts when you need to get user consent and clarify burn policy; auditors get the burn‑auth semantics. (eip.fun)
• Make revocation standard: use VC Bitstring Status Lists alongside EAS revocation attestation; steer clear of custom APIs that could mess with verifiers. (w3.org)
• Opt for SD‑JWT for selective disclosure right now; think about BBS+ if you need unlinkability and your verifier setup can handle it. (rfc-editor.org)
• If you're issuing a bunch of different types each cycle, batching with ERC‑1155 (5633) is the way to go; pair it with rollup fee windows and predictable Layer 2 base fee policies. (eips.ethereum.org)
• Get ready for eIDAS/EUDI wallet interoperability and OpenID compliance--procurement teams will definitely bring it up. (consilium.europa.eu)
• Need anonymous attestations, like for bias-reduced hiring screens? Layer on some ZK-proof options (Semaphore/MACI) on top of VC possession instead of using them as a swap-out. (docs.semaphore.pse.dev)

---

ROI and GTM metrics we sign into pilot SLAs

We steer clear of vanity metrics. Here are the key “money phrases” that really get your CFO and auditors' attention:

• Verification cost per check: We’re aiming for at least an 80% drop in costs compared to those manual HR/email checks by switching over to OIDC4VP and using automated status list lookups. (openid.net)
• Issuance throughput: We’re targeting to churn out at least 10,000 credentials per hour on Layer 2 using ERC-1155 batching--oh, and no weekend cutovers, please! (eips.ethereum.org)
• Audit cycle time: Let’s work on slashing the time it takes to prep evidence from weeks down to under 48 hours! We can do this by tapping into on-chain events, EAS UIDs, and VC status lists. (easscan.org)
• Compliance coverage: Our goal is to map 100% of credential workflows to the NIST 800-63-4 federation and privacy controls. Plus, we’ll need to document our DPIA and retention policies. (pages.nist.gov)
• Interoperability readiness: We'll align VC 2.0 with OIDC4VCI/4VP and have a self-certification plan set for 2026--let’s also work on minimizing RFP risks while we’re at it! (w3.org)

We’ll set up the pilot to keep track of these with clear dashboards and provide Procurement with all the necessary artifacts.

---

Procurement checklist (what your RFP should require)

• Standards: We're talking about ERC‑5192, 5484, 5633, VC 2.0, OIDC4VCI/4VP, and SD‑JWT (plus optional Data Integrity), along with EAS for attestations. Check out the details here.
• Compliance: We’ve got a solid setup with SOC 2/ISO 27001 mapping, and we’re right in line with NIST 800‑63‑4. We're also covering GDPR and FERPA with DPIA and revocation using Bitstring Status List. Learn more here.
• Interop: Planning to have EUDI wallet compatibility by 2026, plus there’s an OpenID self‑cert plan in the works. For more info, head over here.
• Economics: We're looking at L2 issuance with clear fee controls--think minimum base fees. Check the specifics here.
• Security: We emphasize independent audits, solid key management, and well-documented incident runbooks. Also, we keep change logs and do version pinning for cryptosuites to ensure everything stays secure.

---

What you get with 7Block Labs

• A top-notch SBT + VC 2.0 credentialing system that your auditors, HR teams, and regulators can check on their own.
• Interoperability that sticks around longer than any one wallet, LMS, or badge vendor.
• Smart architecture and code that strike the right balance between Solidity pragmatism and privacy-preserving ZK options--focused on real ROI and procurement results, not just the latest trends.

Check out our smart contract development, web3 development services, blockchain integration, and security audit services to find out how we can integrate this into your tech stack.