<story><title>Tesco Discount Barcodes, Cracked</title><url>http://mtdevans.com/projects/barcode/</url></story><parent_chain><item><author>jgrahamc</author><text>While it&apos;s cool to reverse engineer stuff like this and talk about the vulnerability, the final part of the blog post indicates that the person intends to &apos;test it&apos;. This is just a &apos;modern&apos; equivalent of the old scam of removing price labels (remember those) from cheap items and sticking them on expensive ones. That was commonplace enough that the labels themselves were made in multiple parts so that removing them was messy.&lt;p&gt;&apos;Testing it&apos; is a bad idea on two fronts: (a) it&apos;s fraud and (b) he&apos;s actually gone and told everyone he&apos;s going to do it.&lt;p&gt;If the supermarkets were losing a lot of money on this then I&apos;d imagine they&apos;d move to a more secure barcoding scheme.&lt;p&gt;Also, I wouldn&apos;t be surprised if the &apos;red&apos; number was related to the weight of the item as this would be needed for the self-checkout tills.</text></item></parent_chain><comment><author>petercooper</author><text>My wife (a regular Tesco customer) notes that Tesco has price scanners located around the stores so you can check the prices of items on the go. In theory, you could run a test using one of those scanners and simply have a picture of the barcode on an iPhone/printed/whatever. No fraud necessary.</text></comment>
<story><title>Tesco Discount Barcodes, Cracked</title><url>http://mtdevans.com/projects/barcode/</url></story><parent_chain><item><author>jgrahamc</author><text>While it&apos;s cool to reverse engineer stuff like this and talk about the vulnerability, the final part of the blog post indicates that the person intends to &apos;test it&apos;. This is just a &apos;modern&apos; equivalent of the old scam of removing price labels (remember those) from cheap items and sticking them on expensive ones. That was commonplace enough that the labels themselves were made in multiple parts so that removing them was messy.&lt;p&gt;&apos;Testing it&apos; is a bad idea on two fronts: (a) it&apos;s fraud and (b) he&apos;s actually gone and told everyone he&apos;s going to do it.&lt;p&gt;If the supermarkets were losing a lot of money on this then I&apos;d imagine they&apos;d move to a more secure barcoding scheme.&lt;p&gt;Also, I wouldn&apos;t be surprised if the &apos;red&apos; number was related to the weight of the item as this would be needed for the self-checkout tills.</text></item></parent_chain><comment><author>omh</author><text>&lt;i&gt;Also, I wouldn&apos;t be surprised if the &apos;red&apos; number was related to the weight of the item as this would be needed for the self-checkout tills.&lt;/i&gt;&lt;p&gt;The original barcode (which is still present as part of the discounted code) should allow the tills to look up the weight.</text></comment>