Unlike Bitcoin, where every transaction is permanently recorded on a public blockchain, Monero uses ring signatures, stealth addresses, and RingCT to hide the sender, receiver, and amount of every transaction by default. There is no opt-in privacy - every Monero transaction is private from the moment it is broadcast to the network.
When you combine Monero with Tor, you add network-level anonymity on top of protocol-level privacy. Your ISP cannot see that you are interacting with the Monero network, and Monero nodes cannot see your real IP address. This two-layer approach eliminates both blockchain analysis and network surveillance as attack vectors against your financial privacy.
Monero's privacy is not theoretical - it has withstood years of scrutiny from blockchain analysis firms, law enforcement agencies, and academic researchers. The IRS even offered a $625,000 bounty for anyone who could break Monero's privacy, which remains unclaimed.