Which Blockchains Are Going Private?

The list keeps growing. Sui, zkSync, Polygon, and Solana were all built as fully transparent public networks, and all four are now adding confidential transactions. Cardano's new Midnight sidechain is doing the same for that ecosystem. The goal is not anonymity. It is privacy that banks, auditors and regulators can sign off on.

Why the sudden rush to hide transactions?

Public blockchains were built on transparency; anyone can read every balance and every transfer. That was a selling point for years. It is now a barrier to the institutions that crypto spent 2025 courting. A bank will not run payroll, treasury moves, or client settlement on a ledger where competitors can watch in real time. Tokenized real-world assets, encrypted stablecoin flows, and compliant DeFi all need a way to keep amounts and counterparties private while still proving the math is correct.

The common thread is confidentiality, not anonymity. The details of a transaction stay hidden from the public while the network can still verify them, and most of these chains let users reveal specific data to an auditor or regulator when required. It is privacy built for regulated finance, not for dodging it.

The public chains going confidential

Four networks are driving the trend, each with a different approach and a different stage of progress.

Sui

Co-founder Adeniyi Abiodun confirmed on June 5 that Sui (@SuiNetwork) Confidential Transfers are coming this year. The feature uses range proofs to hide transfer amounts while still enforcing supply, so unauthorized minting stays impossible by design, per Abiodun. It sits inside a broader 2026 roadmap that already includes gasless stablecoin transfers, on a network that has processed more than $1 trillion in stablecoin volume since August 2025. No firm launch date has been given.

zkSync

Matter Labs has built its institutional play around Prividium, private permissioned chains that run as validiums. Execution and data stay off-chain in infrastructure that the institution controls, and only a zero-knowledge proof settles to Ethereum. The first production deployment, Memento ZK Chain, was built with Deutsche Bank. A separate effort, the Cari Network, is onboarding five US regional banks with more than $600 billion in combined deposits, with a pilot targeted for the third quarter of 2026.

Polygon

In May, Polygon (@0xPolygon) added a privacy configuration to its Chain Development Kit, letting institutions launch private chains that still tap public liquidity through AggLayer. Built with Succinct Labs, the setup keeps raw transaction data inside institution-owned infrastructure and sends only a cryptographic commitment and a proof to Ethereum. The principle Polygon repeats is private data, public verification. It fits the company's Open Money Stack framing as it winds down its zkEVM mainnet beta.

Solana

@solana got here first, but with an asterisk. Its Confidential Transfers were shipped inside the Token-2022 standard, using homomorphic encryption and zero-knowledge proofs to hide transfer amounts and balances, with an optional auditor key for compliance. The catch is that the ZK ElGamal proof program the feature relies on has been switched off on mainnet since mid-2025, after a researcher discovered a flaw that could have enabled the forging of valid proofs. It stays disabled pending a security audit, so confidential transfers are not usable on the live network for now.

Where does Midnight fit?

Midnight is not a public chain bolting on privacy. It is a new privacy-first sidechain that extends Cardano. It launched a federated mainnet on March 31, 2026, with Google and Vodafone among the node operators. It uses a dual-token model, NIGHT for governance and DUST for transaction costs, plus a dedicated language for confidential smart contracts. Founder Charles Hoskinson (@IOHK_Charles) calls the approach "rational privacy" and has made it clear that Midnight is not chasing Monero's users. Selective disclosure is built in, aimed at finance, healthcare, and identity rather than anonymity.

Who else is doing this?

The names above are the loudest examples, not the whole field. On the $XRP Ledger, @Ripple researchers have proposed a confidential token standard, XLS-0096, that would encrypt balances and transfer amounts for issued assets using EC-ElGamal encryption and zero-knowledge proofs while keeping the total supply public. It is still a proposal moving through XRPL's amendment process, though contributors were pushing it again as recently as this week.

The impulse predates 2026, too. Litecoin (@litecoin) added optional confidential transactions through its MimbleWimble Extension Blocks back in 2022, and $BTC payments routed over the Lightning Network stay off the main ledger entirely, keeping most of their detail out of public view as a byproduct of moving off-chain. Privacy is no longer a niche pursued by a few dedicated coins. It is becoming a feature that nearly every serious network expects to offer.

The private-by-default originals

Set against all of this is a group of chains that treated privacy as the default from day one.

• Monero ($XMR) hides sender, receiver and amount on every transaction through ring signatures, stealth addresses and RingCT. There is no opt-out. That purity is also its problem: exchanges including Binance and OKX have delisted it, and it trades largely outside regulated venues. Its FCMP++ upgrade, now on a beta test network, replaces ring signatures with full-chain membership proofs to widen the anonymity set further.
• Zcash ($ZEC) offers a choice. Transactions can be transparent or shielded with zk-SNARKs, and viewing keys allow selective disclosure. That flexibility helped it overtake Monero in market value in late 2025 and gave it a cleaner story for regulated products, though a recently disclosed vulnerability in its Orchard component has tested confidence.
• Canton (@CantonNetwork) is the institutional take on private-by-default. Built for regulated finance, it keeps transaction details visible only to the parties involved. DTCC is tokenizing US Treasuries on it; JPMorgan is bringing its deposit token across; and Visa joined as a Super Validator in March, one of the current 55 helping to govern the network.

Confidentiality versus anonymity is the real divide

Sorting these chains into public or private misses the actual split. The public chains adding privacy and the institutional natives like Canton are converging on one model: encrypt the details, keep public verifiability, and allow selective disclosure. The genuinely different animals are Monero and, when shielded, Zcash, where the point is to make transactions unlinkable rather than merely confidential.

That difference decides who can use what. Confidential designs keep composability, liquidity and a route through compliance, which is why banks are circling Sui, zkSync, Polygon, and Canton. Mandatory anonymity buys stronger privacy at the cost of exchange access and liquidity, as Monero's delistings proved.

The chains chasing institutions are betting that selective disclosure is enough. Does a network where the right authority can always look count as private, or just as transparent to a smaller audience?

Sources

• ZKsync Prividium documentation explaining how Prividium private validium chains keep data off-chain while anchoring proofs to Ethereum.
• Polygon Labs blog describing the CDK privacy configuration, AggLayer connectivity and the Open Money Stack.
• Solana Docs on the Confidential Transfer extension, noting the ZK ElGamal proof program is temporarily disabled on mainnet pending a security audit.
• Canton Network primary page on DTCC's plan to tokenize Treasuries on Canton.