I get dozens of emails a week from PR firms breathlessly announcing the latest addition of “blockchain technology” to the toolsets of their clients. Most of these puffs are idiotic, but every so often they involve a large and ostensibly serious company.

Like Walmart. Today I find this report in the New York Times:

When dozens of people across the country got sick from eating contaminated romaine lettuce this spring, Walmart did what many grocers would do: It cleared every shred off its shelves, just to be safe.

Walmart says it now has a better system for pinpointing which batches of leafy green vegetables might be contaminated. After a two-year pilot project, the retailer announced on Monday that it would be using a blockchain, the type of database technology behind Bitcoin, to keep track of every bag of spinach and head of lettuce.

Impressive, eh? By this time next year, more than 100 farms that supply Walmart with leafy green vegetables will be required to input detailed information about their food into a blockchain. But… said blockchain will be run and — one presumes — hosted on IBM servers. Since the essence of a blockchain is that it’s a public ledger (so that control and oversight is decentralised) one wonders how a blockchain run on IBM servers is anything other than a fancy ol’ database?

LATER: From the you-couldn’t-make-it-up department, the UK Chancellor of the Exchequer (Finance Minister), when asked (at the Tory Conference) how the government planned to avoid having a hard border in Northern Ireland, replied: “There is technology becoming available (…) I don’t claim to be an expert on it but the most obvious technology is blockchain.”