The Royal Mail hasn’t just lost your item, it’s lost the plot completely.
While the news media has been obsessed with what civil servants might have been doing after work in Downing Street they have overlooked the latest bonkers development from the Post Office – “digital stamps”.
The gimmick is that every new stamp will have a 2D barcode on one side. According to the Royal Mail’s Nick Landon, “Introducing unique barcodes on our postage stamps allows us to connect the physical letter with the digital world and opens up the possibilities for a range of new innovative services in future.” This was followed by promises that it would be possible to link the codes to videos, and by scanning them with an App you could send “birthday messages” and other videos.
Just because something’s possible, it doesn’t mean its a good idea Nick! But what’s the harm, eh?
Well look a bit further – from the start of 2023 you won’t be able to use any of your existing stamps. That’s right – they’re being withdrawn. In a statement Royal Mail has said:
“Mail posted with non-barcoded Definitive stamps after 31 January 2023, will be treated in the same way as if there is insufficient postage on an item….Any item that has insufficient postage is subject to a surcharge. Surcharge fees can be found on our website.”
What you’re supposed to do now is find all your “old fashioned” stamps and post them off to the Royal Mail, who will send you the new digital ones in return. What a waste of time and money – theirs and ours. Why not just accept the old stamps people have paid for until they run out? I’ve asked but received no further comment.
So let’s just assume the Royal Mail hasn’t completely lost its senses and there’s a better reason for this than using an App to “send” Shaun the Sheep videos, or to make money by cancelling stamps already paid for that people won’t get around to replacing in time.
One answer would be to make the stamps machine readable. Possibly, but that’d also make them much easier to forge. You could machine-read an existing stamp anyway; barcode technology is quicker and more forgiving, which is also its weakness.
Perhaps they’re worried about counterfeit stamps? Printing a barcode isn’t difficult. Unless…
I’ve looked at the stamps and they’ve got what’s probably a 47×16 matrix. Allowing for ECC and alignment marks that’s still going to be something like a 480-bit number – enough to give every stamp printed its own serial number from now until the end of time. This would also explain how scanning one could be used to deliver a unique video message to the recipient. If this is the plan – every stamp is unique – they could spot when the same stamp passed through their scanners twice, thus spotting when a forgery has been used.
The flaw in this brilliant plan is that the Royal Mail will have no way of telling if the stamp its currently scanning is the original or the forgery. If a forger has used your stamp number before you did, I predict an almighty row.
Forging the stamps can be made impossible by means of digital signatures. Here is a simple scheme. The plaintext consists of the words Royal Mail, followed by the serial number of the stamp. That is then encrypted, and if you create a forged pattern, when that’s decrypted, it won’t produce the pattern required, that is, the words words Royal Mail followed by a number.