Google wallet now includes ZKP capabilities, initial users include Rail Delivery Group for verifying age requirements when purchasing railcards. Google’s system will be open-sourced.
Threshold cryptography refers to a cryptosystem where the private key is split among multiple parties, with some number of parties (exceeding the threshold) needing to agree to decrypt a message, or produce a signature.
A system is referred to as a (,)-threshold, if at least of these parties can efficiently decrypt the ciphertext/produce a signature.
First system in 1994 by De Santis, Desmedt, Frankel, Yung.
Historically, only orgs with very valuable secrets such as certificate authorities, the military, and governments used the technology.
In March 2019, [[NIST]] conducted a workshop on threshold cryptography to establish consensus on applications, and define specifications. In July 2020, they published a roadmap towards criteria for said schemes.
Threshold versions of schemes can be built for many asymmetric cryptographic schemes. The goal of such schemes is to be as secure as the original scheme. Such schemes include: