  Under Know Your Customer (KYC) regulations, financial institutions are
required to verify the identity and assess the trustworthiness of any new
client during on-boarding, and maintain up-to-date records for risk management.
These processes are time consuming, expensive, typically have sub-par
record-keeping steps, and disadvantage clients with nomad lifestyle. In this
paper, we introduce KYChain as a privacy-preserving certification mechanism
that allows users to share (certified) up-to-date KYC data across multiple
financial institutions. We base KYChain on immutable ledgers and show that it
offers confidentiality and certification compliance of KYC data.
