Umbra

Umbra is a privacy layer for Solana tokens (SPL and Token-2022). Its core business includes two independent tools: EncryptedTokenAccounts, which hide token balances via Arcium's multi-party computation (MPC) so that no single party can decrypt the amount; and a Stealth Pool, which uses an Indexed Merkle Tree and zero-knowledge proofs to break the on-chain link between sender and recipient. Users can also grant selective viewing access to auditors or regulators. The market pain point is that all Solana transactions are public by default—wallet balances and transfer history are visible to anyone, which is unacceptable for payroll, business payments, and personal finance. Previous privacy solutions relied on obfuscation, intermediaries, or zero-knowledge systems that are not suited to multi-party transactions. Umbra's core differentiator is trustless encrypted execution: MPC computation happens off-chain with two on-chain transactions (a handler that queues computation and a callback that posts results), meaning no single node can decrypt data at any stage. In the past six months (2026-03-13 to 2026-09-13), Umbra opened its privacy wallet to the public, enabling shielded transfers, encrypted swaps, and compliance tooling, and released its SDK for developers. However, in a notable negative event, Umbra temporarily shut down its official frontend (switching it to maintenance mode) after approximately $800,000 in stolen funds from the Kelp exploit were moved through its protocol. The team stated this was to avoid hindering recovery efforts, but acknowledged that because the protocol is open-source, the smart contracts remain accessible and the frontend shutdown is largely symbolic.