ELI5 Locks and Keys - could your key open a stranger's door?

Did you know a standard lock might have thousands of combination possibilities, yet yours might open someone else's door? How does a master key work such that it can open multiple locks without compromising security entirely? What makes lockpicking more of an art than a science, requiring skill and a deep understanding of how locks function? How can a particular ""jiggle-and-twist"" method sometimes allow a key to open unintended locks successfully? What surprising connections do locks and keys have with human ingenuity and security throughout history? ... we explain like I'm five Thank you to the r/explainlikeimfive community and in particular the following users whose questions and comments formed the basis of this discussion: QvttrO, TehWildMan_, DJpng, thephantom1492, Childofglass, Jack_Chronicle, Git_Off_Me_Lawn, woofle07. To the community that has supported us so far, thanks for all your feedback and comments. Send us an e-mail: [email protected]