Blockchain is an expandable list of connected records - or blocks - that each contain data representing an individual transaction by members of a network. The information in a single block cannot be altered without changing all the subsequent blocks and alerting the record-keepers in the network that it has been tampered with. For a more detailed explanation of block chain, click here.
The digital thread was created to replace 2D design and fabrication information, what we know as blueprints, that has traditionally guided a product through its manufacturing lifecycle. However, it requires humans to interpret, translate, re-enter and transmit data at each step. Processes using the digital thread method rely instead on a set of 3D digitised instructions that can be electronically exchanged and processed from start to finish, saving time, money and the risk of human error. Because the steps in the process are aligned chronologically, just like financial transactions, blockchain is well-suited to provide a digital thread network with the same protection it gives to cryptocurrencies.
"In other words, if I'm a manufacturer making a part for a product and I receive the specs for that part from the designer who's upstream in the process, blockchain ensures that I can trust the data actually came from that person, is exactly what he or she sent, and was not interfered with during transmission," said NIST research associate and computer scientist Sylvere Krima, the lead author of the new report. "Because the chain is tamper resistant and the blocks are time stamped, a blockchain is a robust solution to authenticate data at any point during the product lifecycle."
In their report, Krima, along with NIST mechanical engineer, Thomas Hedberg, and co-author, Allison Barnard Feeney, describe potential digital threats to smart manufacturing such as product data theft, tampering and corruption. They then show how blockchain can help reveal and thereby deter these threats, which could each produce catastrophes in the manufacturing process.
"For instance, we give the example of product data being sent by a designer to one manufacturer who then must transmit updated data to a second manufacturer for further product processing," Hedberg said. "If a data thief, someone we call a 'bad actor,' grabs the file from Manufacturer 1 and attempts to send Manufacturer 2 a fake data file to cover his crime, Manufacturer 2 will know something's wrong because the true file's blockchain fingerprint won't be there."
The NIST report also details codes and statements in the Unified Modeling Language (UML), a standardised system for computer modeling, that are needed to successfully apply blockchain to a smart manufacturing network.
"Following our reference information model will enable users to authenticate everything within their blocks: where are the data coming from and going to, who is executing the data exchanges, when are the exchanges taking place, what is being exchanged, and how are the exchanges being conducted," Krima said.
"The goal of this reference model is to secure the digital thread for smart manufacturing while enhancing collaboration and establishing trust between production partners," Hedberg said.
To further illustrate blockchain's value to smart manufacturing, a second NIST report features case studies from three different industrial sectors - additive manufacturing, autonomous vehicles and pharmaceutical - showing how the cybersecurity and traceability system would work for each.
