In 2017, I participated in the IPP in Paris.
IPP stands for the International Puzzle Party, an annual gathering of puzzle designers, collectors, and enthusiasts from around the world. One of the highlights is the Exchange event, where each participant brings a new puzzle they have designed, makes enough copies for every other participant, and exchanges with everyone in the room. You arrive with one puzzle and go home with dozens of new ones. It is one of the most generous traditions in the puzzle world.
I decided to try to create a new lock puzzle for my first Exchange.
I went in without any special pretensions. I did not fully realize at the time how rare it is to release a puzzle like the DanLock, a commercial padlock modified from the inside into a brain teaser. My father had done it with the DanLock in 1996, and it had become legendary in the puzzle community. I was not thinking about legacy. I just wanted to make something good enough to bring to Paris.
⚠️ SPOILER ALERT!!! ⚠️
The main trick of the puzzle involved hiding a pin inside the key itself, something I had treated as completely impossible until I met a friend, a mechanical engineer, who described the exact method to achieve it. On the other end of the puzzle was the lock itself. For this, I worked closely with the lock factory owner, who was incredibly happy to cooperate with me, continuing the wonderful relationship he had shared with my father. Together, we tested many prototypes and eventually found a clever way to completely block the key from entering the keyhole until you properly use the hidden pin.
The B-Lock turned out to be more than just a successful entry.
The success at the event was beyond anything I expected. People asked to buy copies on the spot. They were excited that there was a "next generation" of the DanLock. The B-Lock revealed an innovative and special trick that the community had not seen before, and it quickly became a puzzle that people genuinely loved.
It was my first lock puzzle, and it opened a whole new world for me when I realized I could actually come up with many complex designs entirely on my own. It gave me a massive appetite to create more of them.
Everything that came after, the B-Lock II, the Loki, the LoopHole, the PicoLock, the Ant Hunt, the Locus, started in that room in Paris in 2017.
Boaz Feldman
If you want to try the B-Lock or explore the full Puzzlocks collection, the buyer's guide is the best place to start:
How to Choose the Right Puzzle Lock
Or go straight to the B-Lock: