Definition
Address reuse is the practice of sending or receiving cryptocurrency multiple times using the same public address instead of generating new ones. On transparent blockchains such as Bitcoin, this behavior creates a persistent link between transactions that can be analyzed on-chain. As a result, observers can more easily correlate balances, transaction history, and counterparties associated with that address. Address reuse is therefore treated as a security and privacy risk rather than a neutral usage pattern.
Because blockchain data is permanent and publicly accessible, address reuse amplifies the long-term visibility of a user’s financial activity. Once an address is associated with an identity, all past and future transactions involving that address become easier to attribute. This can expose sensitive information about holdings, spending patterns, and relationships between different entities. In some threat models, it may also increase the likelihood of targeted attacks against high-value addresses.
Context and Usage
In systems like Bitcoin, addresses are designed to be disposable identifiers rather than long-term accounts, and address reuse runs counter to this design assumption. Wallets that generate a fresh address for each payment aim to reduce the analytical value of on-chain data, while reuse concentrates activity into a single, easily trackable point. This makes clustering and de-anonymization techniques more effective for anyone monitoring the blockchain.
Address reuse is discussed primarily in the context of privacy-preserving and security-aware transaction practices. It is relevant to both individual users and services that handle large transaction volumes, since systematic reuse can expose entire flows of funds. In security and compliance assessments, repeated use of the same address is often treated as a red flag for weakened privacy posture and increased traceability risk.