The exploit in Onity programmable keycard locks was revealed by [Cody Brocious] at the Blackhat conference. Apparently the DC barrel jack on the outside of the lock serves as a one-wire protocol ...

I am reviewing the Straplok 35/850 wearable model, but it also offers the Chainlok 10, which uses the same wearable adapter and lock barrel but gets a much higher Diamond Sold Secure rating.