QR code phishing has emerged as a serious threat. A retrofit variation that uses cryptographic security and can even work offline might just be the solution.

If a code appears someplace unexpected, inspect it first. If it contains a URL with misspellings, the code could be a sign of fraud. Beware QR codes received unexpectedly.

QR codes are a variation of the typical barcode, capable of collecting information in computer language -- in a two-dimensional matrix of black and white pixels -- when scanned with a scanning device.