Credit card numbers, checksums, and hashes. The story of a robocall scam

As  Lívia and I were out walking Molly and Patty on Monday evening, I received a telephone call from an unknown number. I decided to answer the phone anyway, and I was greeted by a recorded voice telling me that my Bank of America debit card beginning with 4217 has been limited and whether I […]

“Check out my debit card!” Or: why people make bad security choices

Yes, the stories are true, and no, this isn’t The Onion. People are, once again, displaying their affinity for tweeting photos of things that should never be tweeted. Let’s set the scene and put you in the shoes of a number of today’s (possibly young, possibly naïve) Twitter users: you get your first debit card, […]