Walmart’s Veggie-Tracking B.L.T.: Blockchain Lettuce Technology
[Confused about blockchains? Here’s what you need to know.]
The blockchains being tested by companies, including the version adopted by Walmart, generally have nothing to do with Bitcoin or any cryptocurrency — they are entirely new databases with no coins involved. And unlike the Bitcoin blockchain, which can be viewed by anyone, only certain people will be able to view and access the Walmart database.
The system that Walmart is using, IBM Food Trust, has been developed for consumer companies, including Dole, Wegmans and Unilever, to track products moving through the supply chain.
At each stop along the way, people handling produce for Walmart will make an entry on the blockchain, signing off when they receive it and then when they move it onto the next person in the chain. IBM and Walmart say they are already tracking other products like yogurt and poultry on the system.
Blockchains are supposed to make it possible to keep updated databases without any central authority in charge. But currently, all of the records for the Walmart blockchain are being stored on IBM’s cloud computers, for Walmart’s use. That has led to questions about why a distributed database like a blockchain is even necessary.
“The idea is right but the execution seems off,” said Simon Taylor, the co-founder of 11:FS, a consulting firm that advises companies on blockchain adoption. “IBM took new tech that doesn’t need a middleman and made themselves the middleman.”
Ms. McDermott said that the data would be encrypted in a way that will make it impossible for IBM to access or change it.
Efforts to track goods on blockchains have also faced a more fundamental challenge. A blockchain can capture the digital record of a box of spinach. But it cannot tell if someone opened the box and changed the spinach inside, replacing it with arugula or illegal drugs.