Monero hides the sender, the receiver and the amount of every transaction by default, but transactions still exist on-chain and can be disclosed with keys and proofs
Monero uses ring signatures, stealth addresses and RingCT to hide who sent a payment, who received it and how much, and privacy is mandatory for every transaction (getmonero.org). Each transaction still has an ID and a visible fee. Sender privacy rests on a ring of 16 possible inputs, and an owner can reveal incoming payments with a view key or prove a payment with a transaction key.
A signature that mixes the real input with decoys, so an observer cannot tell which one was spent. Monero's ring size is 16: one real input plus 15 decoys, which gives the sender plausible deniability rather than certainty (Monero docs).
What does Monero hide and what stays visible?
Hidden by default
- Sender: ring signatures, ring size 16.
- Receiver: stealth addresses, a one-time address for every payment.
- Amount: RingCT, mandatory since September 2017.
Visible on-chain
- The transaction itself, identified by a transaction ID.
- The fee, which is not encrypted.
- Proof that no coins were created, which anyone can verify.
- 16ring size: one real input plus 15 decoysdocs.getmonero.org
- 11 → 16ring size change in the August 2022 network upgradegetmonero.org
- 2017year RingCT became mandatory for all transactionsgetmonero.org
Amounts are hidden with Pedersen commitments, so nobody sees the value, yet anyone can verify that no coins were created out of thin air.
Can a Monero payment be proven or disclosed?
Monero describes itself as private, optionally transparent. The owner decides what to reveal:
- View key
Sharing the private view key reveals incoming transactions to that wallet, without the ability to spend.
- Payment proof
A sender proves a payment by giving the verifier the transaction ID, the transaction key and the recipient address.
- Spend proof
Shows that you made a specific payment.
- Reserve proof
Shows that a wallet holds at least a given balance.
A view key shows incoming transactions but not outgoing ones reliably, so a balance seen through a view key alone is not reliable (Moneropedia).
A transaction proof shows that funds were sent to an address, not that they are still unspent.
Is Monero really untraceable?
Nothing about a Monero transaction is visible.
Transactions exist on-chain with an ID, and the fee is visible. What is hidden is who sent, who received and how much.
Nobody can ever prove who paid.
The sender can prove a payment with the transaction key. To outsiders, sender privacy is probabilistic: one real input among 16.
Subaddresses can never be linked.
Sending the balances of several subaddresses in one transaction links them on the blockchain (Monero docs).
On-chain privacy covers the network layer too.
Dandelion++ makes linking a transaction to an IP address harder, but per Monero's docs it does not protect against the ISP or VPN provider or the first remote node.
Is Monero fungible?
Because every transaction hides its history, Monero is designed so that any 1 XMR can be swapped for any other 1 XMR. That is the property privacy is meant to protect.
Swapping Monero
SimpleSwap and ChangeNOW both list XMR.
A swap to or from Monero works like any other order, and the address is the part to check: 95 characters for a standard address or subaddress, 106 for an integrated one.
Step by step in Swapping Monero (XMR), and why services screen addresses in Address screening.
Questions
Is Monero really untraceable?
Monero hides the sender, receiver and amount of every transaction by default.
Transactions still exist on-chain with an ID and a visible fee, sender privacy is probabilistic with a ring of 16, and owners can disclose payments with view keys and proofs.
What can you see on the Monero blockchain?
That a transaction happened, its transaction ID and its fee, and cryptographic proof that no coins were created. Not the sender, the receiver or the amount.
What is ring size in Monero?
The number of possible inputs in each ring signature: 16, one real input plus 15 decoys. It went from 11 to 16 in the August 2022 network upgrade.
What is a Monero view key?
A key that reveals the incoming transactions of a wallet without allowing spending. It does not show outgoing transactions reliably.
How do I prove a Monero payment was sent?
Give the verifier the transaction ID, the transaction key and the recipient address. The wallet can also produce spend proofs and reserve proofs.
What is Dandelion++ in Monero?
A change to how transactions spread across the network that makes it harder to link a transaction to the IP address that sent it.
It does not protect against the ISP or VPN provider or the first remote node.