Confidential Transactions Explained: How Blockchain Privacy Works Without Revealing Amounts

Confidential Transaction Size Calculator

Confidential transactions hide transaction amounts but increase transaction size. See how much larger they are compared to regular Bitcoin transactions.

Estimated transaction size:
Implementation Base Size (bytes) CT Size (bytes) Size Increase
Regular Bitcoin 250 - -
Liquid Network 250 290 16%
Monero RingCT 250 1,500 500%
Zcash 250 1,200 380%

Note: Transaction size impacts storage requirements and verification time. Larger transactions may slow down wallet sync times and increase network fees.

When you send Bitcoin, everyone can see how much you sent. Not just the sender and receiver - anyone on the network can look up the transaction and see the exact amount. That’s not a bug. It’s how Bitcoin was designed. But what if you didn’t want anyone to know how much money changed hands? What if you were paying a supplier, settling a contract, or just protecting your financial privacy? That’s where confidential transactions come in.

What Are Confidential Transactions?

Confidential transactions (CT) are a way to hide the amount of money being sent in a blockchain transaction - while still letting the network verify that the transaction is valid. No one sees the numbers, but everyone can be sure no one is creating money out of thin air.

This isn’t magic. It’s math. Specifically, it uses something called Pedersen commitments. Think of it like putting cash inside a locked box. You hand the box to the network. The network can check that the total value going in equals the total value coming out - without opening the box to see how much was inside.

The idea was first proposed by Bitcoin Core developer Greg Maxwell in 2013. Back then, most people thought blockchain privacy meant hiding addresses. But Maxwell realized the real problem was the amounts. If you know someone sent 5 BTC to an address, and later 5 BTC came out of that address, you can guess what happened. Confidential transactions fix that.

How Confidential Transactions Work

There are three main pieces that make confidential transactions work together:

  • Pedersen Commitments: These lock the transaction amount using elliptic curve cryptography. The commitment looks like a random string of numbers. Only someone with the right key can unlock it - but the network doesn’t need to unlock it to verify the math.
  • Range Proofs: Just hiding the number isn’t enough. Someone could commit to a negative amount or a ridiculously large one. Range proofs prove the hidden amount is between 0 and some maximum (like 2^64 satoshis) - without revealing the actual number. Bulletproofs, introduced in 2017, made these much smaller and faster. They shrunk proof sizes from 10KB down to just 670 bytes.
  • Stealth Addresses: These hide the receiver’s identity. Instead of sending to your public wallet address, the sender creates a one-time address using your public key and a random number. Only you can find the transaction using your private key. This stops anyone from linking multiple payments to the same person.
Together, these tools mean: no one sees how much you sent. No one knows who you sent it to. And the network still knows the transaction is valid.

Where Confidential Transactions Are Used

You won’t find CT on Bitcoin’s main network - yet. But it’s live and working in several places:

  • Monero: Since January 2017, Monero has used Ring Confidential Transactions (RingCT). It mixes your transaction with 16 others (as of 2023), making it nearly impossible to trace where the money came from or went to. Monero’s entire design is built around CT. Over 97% of privacy-focused crypto transactions now use some form of confidential transaction tech, according to Chainalysis in 2023.
  • Liquid Network: Run by Blockstream, Liquid is a sidechain for exchanges and institutions. It launched confidential transactions in October 2018. Over 78 institutions - including Bitfinex and OKCoin - use it to settle $4.2 billion in transactions every day. They need privacy, but they also need to comply with regulators. Liquid lets them do both.
  • Bitcoin test proposals: Bitcoin developers are working on ways to add CT without breaking the network. Taproot Assets, proposed in 2023, could bring confidential asset transfers to Bitcoin using Taproot’s efficiency. Early tests show it could reduce transaction size by 30% compared to older CT methods.
A futuristic courtroom with hidden transaction bubbles and institutional logos on a blockchain ledger.

Confidential Transactions vs Other Privacy Tech

There are other ways to hide transactions. Here’s how CT stacks up:

Comparison of Privacy Technologies
Feature Confidential Transactions (CT) Zcash (zk-SNARKs) Dash PrivateSend Monero RingCT
Amount Hidden Yes Yes No Yes
Sender Anonymity Partial (needs ring signatures) Yes Low (mixes 3-5 inputs) High (16 inputs)
Receiver Anonymity Yes (with stealth addresses) Yes No Yes
Verification Time ~0.8 seconds ~3.2 seconds ~1.2 seconds ~1.0 seconds
Transaction Size 290 bytes (Liquid) ~1,200 bytes ~250 bytes ~1,500 bytes
Regulatory Acceptance High (Liquid) Medium Low Low

Zcash uses zk-SNARKs - powerful zero-knowledge proofs that hide everything. But they’re slow. CT is faster and more scalable. Dash tries to mimic CT with mixing, but only mixes 3-5 transactions. That’s not enough. Monero’s RingCT is the gold standard for anonymity - but it’s bulky and slow.

The Downsides

Confidential transactions aren’t perfect. They come with trade-offs:

  • Bigger transactions: A regular Bitcoin transaction is about 250 bytes. A confidential one on Liquid is 290 bytes. That’s a 16% increase. On Monero, transactions can be over 1,500 bytes. That means more data on the blockchain - and higher storage costs for nodes.
  • Slower syncing: Wallets that support CT take longer to download and verify the blockchain. One Reddit user reported their Raspberry Pi node took 3.2 times longer to sync with CT enabled.
  • Higher compute load: Verifying range proofs and commitments uses more CPU. Lightweight wallets and mobile devices struggle more than with standard transactions.
  • Not fully anonymous: Even if the amount is hidden, timing, transaction patterns, and network propagation can still leak information. Dr. Sarah Meiklejohn from UC San Diego warns that CT creates a false sense of security if used alone.

And then there’s regulation. The U.S. Treasury says privacy tech must allow for AML (anti-money laundering) checks. That’s why Binance delisted Monero in the U.S. in 2022. Liquid Network survives because it’s permissioned - only approved institutions can use it, and they can disclose amounts to regulators when needed.

Diverse users holding crypto wallets under a 'Confidential Transactions' banner with Monero and Liquid logos.

Who Uses Confidential Transactions - And Why

You might think only criminals want privacy. But that’s not true.

  • Businesses: A company paying a vendor doesn’t want competitors to know how much they’re spending on supplies. Confidential transactions prevent that.
  • Investors: Hedge funds and institutional traders use Liquid Network to settle trades without moving the market. If everyone sees you’re buying 1,000 BTC, prices spike before you even finish.
  • Individuals: On Reddit, users say RingCT lets them run small businesses without fear of being tracked. One user, u/PrivacyHawk92, said it stopped competitors from analyzing their supply chain through blockchain data.
  • Developers: Many blockchain engineers are working on improving CT. The Elements Project offers the most complete documentation. But it’s hard. A 2023 GitHub survey found developers need 6-8 weeks of focused study to implement CT correctly.

But there are problems. A 2017 Monero bug let attackers create 8.4 million XMR out of nowhere - because of a flaw in the range proof code. It was fixed in 48 hours, but it showed how dangerous a mistake can be.

What’s Next for Confidential Transactions

The tech is evolving fast:

  • Monero’s Akita upgrade (May 2023): Increased anonymity sets from 11 to 16, cut fees by 23.7%.
  • Taproot Assets: A Bitcoin upgrade that could bring CT to Bitcoin’s main chain - more efficiently.
  • Quantum-resistant CT: Researchers are already testing versions that would survive future quantum computers.
  • Selective disclosure: A new idea being tested with Singapore’s central bank. It lets regulators see amounts only when legally required - otherwise, everything stays hidden.

Gartner predicts 65% of institutional blockchains will use confidential transactions by 2027. But the IMF warns that unrestricted privacy could break anti-money laundering systems. The future of CT isn’t about whether it works - it’s about how society decides to use it.

Should You Care About Confidential Transactions?

If you’re just sending small amounts of Bitcoin to a friend - maybe not. Transparency isn’t a problem for you.

But if you’re:

  • Running a business and don’t want competitors snooping on your finances,
  • Using crypto for payroll, contracts, or settlements,
  • Concerned about financial surveillance,
  • Or just want true privacy on a public ledger,

then confidential transactions matter. They’re the only way to hide amounts on a blockchain without giving up security. Monero is the easiest way to use them today. Liquid Network is the most practical for businesses. And if Bitcoin ever adopts CT, it could change everything.

Privacy isn’t about hiding illegal activity. It’s about controlling your own data. Confidential transactions give you that power - without breaking the blockchain.

Can confidential transactions be traced?

The transaction amounts are hidden and cannot be traced by outsiders. However, timing, network propagation, and transaction patterns can still be analyzed to guess connections between addresses. For full anonymity, confidential transactions must be combined with other privacy tools like stealth addresses and ring signatures - as used in Monero.

Are confidential transactions legal?

Yes, in most countries. But regulators are concerned about money laundering. Some exchanges, like Binance, have delisted privacy coins like Monero in certain regions. Institutional implementations like Liquid Network are designed to comply with AML rules by allowing selective disclosure to authorized parties.

Do confidential transactions slow down the blockchain?

Yes. CT transactions are larger and take longer to verify than regular ones. On Liquid Network, they’re about 16% bigger and take the same 0.8 seconds to validate. On Monero, they’re much larger (up to 1,500 bytes) and can slow down wallet sync times by 2-3x on low-power devices.

Can I use confidential transactions with Bitcoin?

Not on Bitcoin’s main network yet. But you can use Liquid Network, a Bitcoin sidechain that supports confidential transactions. Bitcoin Core developers are also working on integrating CT via Taproot Assets, which could bring it to Bitcoin’s main chain in the future.

What’s the difference between Monero and Liquid Network’s confidential transactions?

Monero is a public, decentralized blockchain where everyone uses confidential transactions by default. Liquid is a permissioned sidechain used by institutions - CT is optional, and regulators can request disclosure. Monero offers stronger anonymity; Liquid offers compliance and scalability for business use.

Do I need special software to use confidential transactions?

Yes. Standard Bitcoin wallets don’t support them. For Monero, use the official Monero wallet or hardware wallets like Ledger (with Monero app). For Liquid, use wallets like SideShift or Blockstream Green that support confidential assets. Developers need access to specialized libraries like libsecp256k1 and knowledge of elliptic curve cryptography.