Umbra Privacy

Umbra is a financial privacy layer for Solana. It provides cryptographic infrastructure for confidential transactions, letting users and applications keep financial data private on-chain while still allowing disclosure when needed.

The protocol supports token transfers and interactions that are anonymous, unlinkable, and auditable. It is built as a shared-state system rather than a per-user one, which is intended to keep privacy costs lower than typical on-chain privacy designs.

Its main features are unlinkable transfers, where the on-chain link between sender and receiver is broken; confidential amounts, where transaction values are encrypted and visible only to the parties involved; relayer support, which lets users submit claim transactions through a relayer for gasless withdrawals to new addresses that have not been pre-funded with SOL; and voluntary auditability, an opt-in mechanism to generate viewing keys that disclose transaction history to third parties for compliance or auditing.