Starknet outlines STRK20 with viewing keys for regulators

STRK20 privacy token standard: token-level privacy by default

Starknet launched the STRK20 privacy token standard to make privacy a native token attribute rather than an external add-on. As reported by The Block, STRK20 embeds shielding in the token itself so balances, senders, receivers, and amounts are confidential by default, while offering viewing keys for regulators and targeting sub‑five‑second settlement with low fees; the design aims to preserve DeFi composability and avoid liquidity fragmentation by eliminating separate wrappers or mixer-style tools.

Because privacy is integrated at the token level, private transfers, swaps, and staking are intended to work within the same asset without isolating liquidity. The framework emphasizes default confidentiality with legal auditability via selective disclosure, which means it is not positioned as absolute anonymity.

Why it matters: private transfers without breaking DeFi composability

Private-by-default assets have typically fractured liquidity or broken app integrations; STRK20 is framed as addressing both. According to PANews, the standard supports account-balance confidentiality and private transfers for any ERC‑20 token, enables private DeFi operations within the same asset, and lets users switch between masked and public states, a duality that helps maintain broad compatibility for stablecoins and wrapped BTC.

StarkWare’s leadership has positioned the standard as infrastructure for mainstream issuers rather than an experimental privacy add-on. “Privacy shouldn’t be an afterthought or a compromise to functionality,” said Eli Ben-Sasson, CEO of StarkWare, emphasizing STRK20’s goal of turning privacy into a token-level attribute.

In practice, the approach is intended to preserve existing DeFi integrations while allowing issuers and users to choose private or public flows as policies and use cases require. The model reduces common objections by combining token-level privacy with selective disclosure pathways for regulated institutions.

How STRK20 shields balances, senders, receivers, and amounts by default

Under STRK20, the token’s state is designed so that account balances and transaction details, sender, receiver, and amount, are hidden from public view by default. Viewing keys for regulators enable selective disclosure to auditors or law enforcement when legally required, aligning confidentiality with oversight needs rather than replacing them.

The dual masked/public modes mean users can transact privately or opt into visible transfers without moving into separate assets, which supports continuity across wallets, exchanges, and protocols. This structure aims to keep DeFi composability intact while enabling private transfers, swaps, and staking as routine operations within a single token contract.