Monero¶

Monero (XMR) is an open-source cryptocurrency created in 2014, focused on privacy, decentralization, and fungibility. Unlike Bitcoin, Monero's blockchain is obfuscated by default -- the sender, receiver, and amount of transactions are all cryptographically hidden, making it one of the most privacy-focused cryptocurrencies today.

Problems It Solves¶

Although Bitcoin is often mistakenly believed to be anonymous, it is actually pseudonymous. Bitcoin's transaction history is completely public on the blockchain, and through on-chain analysis, addresses can be linked to real-world identities (via exchange KYC, etc.).

Monero aims to solve the following core problems: 1. Transaction Traceability: Preventing third parties (governments, analytics companies, criminals) from tracking fund flows. 2. Asset Fungibility: In Bitcoin, if certain coins were involved in illegal activities ("tainted coins"), they may be rejected by exchanges, meaning different bitcoins are not truly equal in value. Since Monero's history cannot be traced, all tokens are completely equal, ensuring monetary fungibility.

Implementation Mechanism and Principles¶

Monero does not rely on a single privacy technology but combines multiple cryptographic protocols to separately protect different parts of transactions.

Ring Signatures - Protecting the Sender¶

Ring signatures allow a sender to mix their public key with other users' public keys ("decoys") to create a signature. To external observers, the transaction could have been initiated by any member of the group, making it impossible to determine the actual signer. This effectively hides the sender's true identity. Monero currently uses the CLSAG (Compact Linkable Spontaneous Anonymous Group) signature scheme, optimizing size and verification speed.

Stealth Addresses - Protecting the Receiver¶

For each transaction, the sender's wallet automatically generates a one-time random address (stealth address) for the receiver. The blockchain records this one-time address rather than the receiver's actual main address. Only someone possessing the receiver's private keys (View Key and Spend Key) can scan the blockchain to identify which transactions are addressed to them. This hides the receiver's identity.

Ring Confidential Transactions (RingCT) - Protecting the Amount¶

Ring Confidential Transactions (RingCT), introduced in 2017, hide transaction amounts. They use Pedersen Commitments and Range Proofs (now upgraded to Bulletproofs) to mathematically prove "input amounts equal output amounts" without revealing specific values.

RandomX Consensus Algorithm¶

To counter the centralization of hashpower caused by ASIC miners, Monero periodically upgraded its PoW algorithm, ultimately adopting RandomX. This is an algorithm optimized for general-purpose CPUs, making consumer-grade CPUs more efficient at mining than GPUs and ASICs, greatly enhancing the network's degree of decentralization.

Key Features¶

Default Privacy: Privacy features are mandatory, not optional. This ensures the entire anonymity set is large enough, maximizing privacy protection.
Dynamic Block Size: Monero has no fixed block size limit; it adjusts dynamically based on network transaction volume, helping maintain low fees under high load.
Censorship Resistance: Since transaction types and participants cannot be distinguished, the network cannot censor or blacklist specific users or funds.
Tail Emission: To ensure long-term network security, Monero maintains a fixed issuance of 0.6 XMR per minute after the main emission phase ends, incentivizing miners to continue maintaining the network.