No. Neither is it an error in the article, since they use the same term in their paper: https://people.eng.unimelb.edu.au/vjteague/UniversalVerifiabilitySwissP

No. Neither is it an error in the article, since they use the same term in their paper: https://people.eng.unimelb.edu.au/vjteague/UniversalVerifiabilitySwissPost.pdf https://people.eng.unimelb.edu.au/vjteague/UniversalVerifiab... It seems there is a class of commitment schemes that's called "trapdoor commitment schemes" and deployed in SwissPost. I'm not aware of these, but they cite this PhD thesis on the topic: https://www.math.uni-frankfurt.de/~dmst/research/phdtheses/mfischlin.dissertation.2001.pdf https://www.math.uni-frankfurt.de/~dmst/research/phdtheses/m... (Disclaimer: I have no idea how these work - maybe the authors mixed up their terminology ;-))