Interview first published in the September/October 2022 issue and posted online in February 2023. CoreLedger co-founder Johannes Schweifer gives his perspective; quoted fees and outlook reflect that period.
Known particularly through cryptocurrencies, blockchain has also been explored in supply chains and distributed manufacturing. This feature examines possible AM applications and their links with the circular economy, without assuming the technology is necessary or profitable in every case.
A blockchain is a shared ledger with cryptographically linked blocks. Access can be public or restricted; not every blockchain is open to everyone. NIST explains its principles and limitations.
In a spare-parts supply chain, file exchange raises questions about provenance, authorized versions, integrity and manufacturing rights. Digital rights management (DRM) can govern file use. It is not synonymous with blockchain, and security controls remain necessary throughout the process.
Johannes Schweifer, CEO and co-founder of CoreLedger, describes approaches explored by his company and the technical conditions for implementing them:
“Additive manufacturing is an ideal solution for rapid prototyping, producing spare parts, and to reduce transportation costs by decentralized manufacturing. The core problem is the prevention of illegal copies, because once you’ve obtained the printing file you can make as many copies as you want. This is where blockchain technology can offer a solution, so most of the technology’s use cases in the industry are therefore based on the prevention of illegal copies. This can be achieved in many ways. One is transparency. Serial numbers can be created on blockchain and integrated into the 3D model. Serial numbers on blockchain are unique by design, so any re-use can be excluded. If this measure alone is not sufficient, it can be propped up with “Track & Trace” on blockchain to follow the path of each printed part.
Another use-case involves the modification of the printer hardware or software (ideally both), so that it requires a “Token” of the design file for every printout.
Blockchain Technology also comes into play when the actual printing file is stored on a decentralized file system such as IPFS, and access rights are administrated by smart contracts. This can be a token or just some digital rights management based on cryptographic proofs.
Apart from prevention of illegal copies, blockchain can help to ensure the quality of a product. This is achieved by transparency too. Deriving a cryptographic fingerprint of data, a so-called “file hash” is key to ensure that a file is not tampered with. When you print a model, you want to make sure that no one has modified it, e.g. reduced or increased wall-thickness or support structures or has changed labels, logos, or other elements. Especially in the area of 3D printing in biotech and medical applications, this security is essential. Blockchain is the perfect tamper proof database, because it doesn’t allow any backwards-modification of data. Those are the most relevant use-cases to-date with an obvious economic benefit ”, Johannes Schweifer, CEO and Co-Founder of blockchain infrastructure company CoreLedger told 3D ADEPT Media. While the current focus is made on the use of blockchain in an AM production environment, CoreLedger’s blockchain platform can be used across various industries.
Clarification: a tamper-resistant ledger is not invulnerable. It does not independently verify incoming data or physical part quality. A hash checks integrity against a trusted reference; copy prevention also requires controls on files and equipment. The NIST report describes these limitations.
CoreLedger presents its Token Economy Operating System (TEOS) as a platform for documentation, tokenization and exchange management. With AMBITORIO AG, it describes a solution intended to limit authorized prints using tokens, subject to hardware and software integration.
In the proposed model, token accounting represents printing permissions. The physical result and any failed build still require separate checks.
The implementation requires decisions about the following components:
- ledger replication and network governance;
- transaction-validation and consensus rules;
- key management, access rights and links to verified identities;
- traceability and checks linking records to actual manufacturing.
These choices vary by application. A digital signature alone does not establish a real-world identity. Confidentiality, equipment integration and quality evidence need explicit design.
Moreover, the combination of challenges raised by each of these use cases also hinders the scalability of the technology within an AM environment – not to mention their cost implications. Emphasizing on some of the challenges and solutions on this road, Schweifer notes:
“First, there is the technical hurdle. Effective copy-protection requires a hardware and software modification. The model itself is just bits and bytes, and there are plenty of ways how to steal it without any blockchain authorization. End-to-end encryption plays an important role here. The second hurdle is the transparency itself. Not every industry is ready for total openness when it comes to providing information about the whereabouts of the printed products. Geolocations, a person’s identity, and even company names could be sensitive. This is especially true in medical and biotech applications. Cryptography can be used to obfuscate the data, but this would reduce transparency. The underlying blockchain is also a challenge. Many proposed solutions are based on Ethereum technology, but they were written when transactions on the Ethereum blockchain were cheap.
In Ethereum, gas measures transaction-execution resources, not a fuel. The amounts mentioned below are historical examples, not a fixed tariff.
“When the gas limit became a problem, transactions became quite pricey. It wouldn’t be economical to pay 30 or 40 USD just to create a serial number on Ethereum. Apart from Ethereum, there are many other choices, but that’s exactly the problem. How can you avoid running into the same cost-problem (…) And which blockchain to choose? In the absence of an industry standard, there is no easy “blockchain of choice” either, and that’s before we get to the question of whether it should be a public or private chain. These questions have to be addressed on a case-by-case and company-by-company basis, depending on their specific requirements. Then there are some practical hurdles. If we assume that the number of copies are limited by the number of tokens, then each token represents the right to print exactly one copy. But 3D printers don’t have a 100% success rate, especially not with complex geometries. Token-based approaches therefore require an automated quality check, which can grant a refund”, he continues.
The business case therefore depends on use, fees, required controls and network governance. A technical demonstration alone does not establish industrial-scale profitability.
Blockchain and the circular economy
Tokens can record permissions or operations, but they do not replace trust in participants, equipment and inspection. The link between the digital record and the physical part still needs to be established.
From a profitability standpoint, the integration of blockchain can be appealing to local manufacturing businesses. While a consortium of companies affirms they have been able to integrate blockchain within a cross-continent distributed Additive Manufacturing environment, I remain very cautious about such deployment given the fact that we still lack viable benchmarks.
Manufacturing closer to the user can reduce some transport and inventory. Environmental performance also depends on energy, materials, scrap and end-of-life. Proximity alone does not guarantee lower emissions. Schweifer proposes the following mechanism:
“It must be possible to recycle 3D printed parts into raw material. Thermoplastics are the most viable material for this purpose, which excludes already some additive techniques. Blockchain Technology comes into play when Track & Trace mechanisms can be used to reward the returning of broken or retired parts into the product cycle. Products can, for example, be labelled with serial numbers and when they are recycled, the serial number is invalidated and some reward tokens are paid, which in turn are used at the beginning of the product cycle, to e.g. pay for printing runs (new serial numbers) or raw materials”.
That scenario requires actual collection, reliable part identification and a suitable material-recycling route. A token recording an operation does not replace evidence that recycling occurred.
Blockchain energy use belongs in the assessment. It varies strongly with the consensus mechanism; a proof-of-work network does not represent every network’s consumption.
We should recognize the fact that, there are a few different varieties of these consensus algorithms to choose from, some of which are better than others. Those consensus mechanisms include Proof of Work (PoW), Proof of Stake (PoS) and Proof of Authority (PoA). It’s up to the user to have a clear understanding of each of them in order to determine what they have to compromise on.
Historical reference: Ethereum switched to proof of stake on September 15, 2022, sharply reducing consensus energy use. That did not eliminate transaction fees or establish an environmental benefit for every blockchain application.
“The current market of blockchain and AM is still in its infancy, with many ideas and projects. Blockchain technology has just overcome its days of extreme hype. NFTs and Tokens overshadowed every alternative use-case for the technology during the past years, drying up funding for non-financial projects. Blockchains kept emerging as well, making earlier implementations on costlier or slower blockchains obsolete. This naturally hampers progress.
Nonetheless, there is now growing interest from the industry. Blockchain technology can ultimately help to save money or to prevent loss, e.g. from illegal copies. That’s certainly not negligible in terms of economic value. The value for blockchain in Additive Manufacturing is clear: To solve the problem of copy-protection (some form of digital rights management, essentially). Blockchain technology is the perfect tool to prevent copies and counterfeits, therefore it is a natural fit for the task. Once designers of 3D models feel safe to publish their files on a blockchain-based digital-rights platform without reluctance, because they know their intellectual property is protected from illegal use, then we’d have achieved a major milestone”, Schweifer concludes.
These concluding remarks express CoreLedger’s perspective at the time. Copy and counterfeit protection remain properties of the whole system that require testing in real conditions.
This dossier has first been published in the September/October edition of 3D ADEPT Mag.
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