Abstract
The invention of the barcode transformed retail and supply chains by providing a universal, machine-readable identifier that ensured accuracy, efficiency, and interoperability across diverse systems. Similarly, Decentralized Identifiers (DIDs) represent a foundational innovation for digital ecosystems: a universal, cryptographically verifiable identifier that enables trusted communication across domains and platforms. This paper explores the analogy between DIDs and barcodes, examining how both enable end-to-end interoperability, reduce friction, and unlock new models of value creation.
Copyright © 2025 Michael Herman (Bindloss, Alberta, Canada) – Creative Commons Attribution-ShareAlike 4.0 International Public License
1. Introduction
In 1974, a pack of Wrigley’s gum was scanned at a Marsh supermarket in Ohio, marking the first use of the Universal Product Code (UPC). That moment marked the beginning of a transformation in retail, logistics, and global commerce. By providing a standardized identifier, barcodes automated inventory management, accelerated checkout, reduced human error, and laid the foundation for today’s global supply chains.
Digital ecosystems in the 21st century face an equivalent problem: how to create universal, secure, and machine-readable identifiers that work across organizations, platforms, and jurisdictions. While domain names, IP addresses, and UUIDs serve as identifiers, none are self-sovereign, portable, and verifiable across trust boundaries. Decentralized Identifiers (DIDs) aim to solve this.
This paper argues that DIDs are the barcodes of digital trust: a universal, machine-readable system for identifying entities in secure communications, enabling a new end-to-end supply chain of digital trust.
2. The Barcode Revolution
2.1 Before Barcodes
- Manual price tags and clerical data entry.
- Inventory tracking prone to human error.
- Inefficient supply chains with frequent stockouts and overstocking.
- Lack of standardization across retailers and manufacturers.
2.2 With Barcodes
- Universal identifiers: UPC and EAN standards.
- Machine readability: fast, automated scanning reduced labor costs and errors.
- End-to-end traceability: from manufacturer → distributor → retailer → checkout.
- Scalability: millions of products, billions of transactions.
Impact: Barcodes enabled just-in-time inventory, global retail expansion, and precise supply chain optimization [Brown, Inventing the Barcode, 2010]. The key insight: a universal, interoperable identifier unlocks systemic efficiencies across the value chain.
3. DIDs: A Digital Barcode for Trust
3.1 What are DIDs?
Decentralized Identifiers (DIDs) are globally unique identifiers that are self-sovereign, verifiable, and resolvable without reliance on centralized registries. Defined by the W3C, DIDs point to DID Documents, which contain public keys, service endpoints, and metadata necessary for establishing secure communication.
3.2 Core Features
- Universality: A DID can represent a person, organization, device, or digital asset.
- Machine readability: DIDs are structured and resolvable by software.
- Cryptographic trust: Integrity and authenticity are verifiable through signatures and key material.
- Decentralization: No single issuing authority required; anyone can create a DID.
- Extensibility: Support for multiple DID methods (blockchain, ledger, peer-to-peer).
3.3 Why It Matters
Just as barcodes freed retail from manual, siloed processes, DIDs free digital ecosystems from centralized identity silos (e.g., social logins, proprietary identity providers).
4. Mapping the Analogy: Barcodes vs. DIDs
Barcode PropertyDID EquivalentImplicationsUniversal product identifierUniversal decentralized identifierEnables global recognition of digital actorsMachine-readableMachine-resolvable DID DocumentAutomated verification by software agentsStandardization (UPC/EAN)W3C DID Core standardCross-platform interoperabilityScannable at every point in supply chainResolvable across trust domainsEnd-to-end verifiable identityFacilitates inventory managementFacilitates trust managementEnsures secure digital transactionsEnables retail efficiencyEnables digital trust ecosystemsReduces cost, friction, and fraud
5. Benefits of the Barcode Analogy
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End-to-End Traceability
- Barcodes track goods from origin to checkout.
- DIDs enable trust from authentication through data exchange to audit.
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Automation and Efficiency
- Barcodes eliminated manual entry; DIDs eliminate manual trust establishment.
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Interoperability
- Any barcode scanner can read a UPC; any DID-compliant system can resolve a DID.
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Scalability
- Barcodes scaled to billions of products; DIDs can scale to billions of devices, people, and services.
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Systemic Transformation
- Barcodes reshaped retail; DIDs could reshape finance, healthcare, IoT, and governance.
6. Limits of the Analogy
- Centralization vs. Decentralization: Barcodes are managed by centralized registries (GS1), whereas DIDs are inherently decentralized.
- Trust Layer: Barcodes encode only identity (the product number), not integrity or authenticity. DIDs add cryptographic verifiability.
- Complexity: Scanning a barcode is simpler than resolving a DID, which requires cryptographic operations and network lookups.
- Adoption: Barcodes achieved rapid, global retail adoption; DIDs remain in early deployment phases.
7. Strategic Implications
7.1 Identity and Access
DIDs could serve as the UPC of digital identity, enabling universal, interoperable identity across organizations.
7.2 Supply Chain and IoT
DIDs can extend barcodes’ logic into digital-physical convergence, providing secure digital twins for physical assets.
7.3 Finance and Governance
DIDs provide the foundational layer of trust for verifiable credentials, smart contracts, and cross-border compliance.
7.4 The “Barcode Moment”
Just as retail only transformed once barcodes were widely adopted, the digital trust economy will require a tipping point of DID adoption to realize systemic benefits.
8. Conclusion
The barcode transformed retail by enabling universal, machine-readable product identification across the supply chain. DIDs can do the same for digital ecosystems by enabling universal, machine-readable, and verifiable identity.
If DIDs achieve broad adoption, they could serve as the universal identifiers of digital trust, enabling secure, scalable, and interoperable communication across the global digital economy — much as barcodes enabled the rise of global retail supply chains.
References
- Brown, George. Inventing the Barcode. MIT Press, 2010.
- W3C. “Decentralized Identifiers (DIDs) v1.0.” https://www.w3.org/TR/did-core/.
- GS1. “History of the Barcode.” https://www.gs1.org/barcodes/history.
- Cameron, Kim. “The Laws of Identity.” Microsoft, 2005.
Inspired by the book Reshuffle by Sangeet Paul Choudary.
Produced as the outcome of a conversation between Michael Herman and ChatGPT. October 1, 2025.