Today (Jan. 31) is the deadline WalMart set for direct suppliers of leafy greens to join its blockchain-enabled food-tracking network. The corporate giant’s latest innovation—which arrived as a mandate—is an admirable step toward improving food traceability and safety, but might seem odd if you’re a blockchain purist.
Blockchains are digital record-keeping systems. They’re similar to databases, except everyone participating in the network can verify when a change has been made. (This is sort of like Google Docs, but it’s an imperfect analogy, because documents have owners who can delete them, and the service depends on one organization, Google.) Also, in a blockchain setup, each change must be processed according to a set of rules before records are updated across the entire network.
For Walmart, these properties are useful in a complex setting like tracking food provenance in a multi-party supply chain. In a simulated recall last year, the company used blockchain to reduce the time it took to trace the origin of a bag of mangoes from almost seven days to just 2.2 seconds.