The​idemixgen​tool is used to create configuration files for the Identity Mixer based MSP
(Membership
Service
Provider)
in
Hyperledger
Fabric.​When
configuring
membership,
the​idemixgen​tool creates three directories:​/ca/,​/msp/, and​/user/1. The​/ca/​directory contains
the issuer secret key, issuer public key, and revocation key, which should only be present for a
Certificate Authority (CA). The​/msp/​directory contains the issuer public key and revocation public
key, which are required to set up an MSP that verifies Identity Mixer signatures.​The​/user/​directory
specifies a default signer configuration1. Therefore, the correct answer is the user directory, which is
created alongside the ca and msp directories by the​idemixgen​tool.
