Briefing
The core research problem is the unexamined privacy risk at the interface between the public network and the blockchain’s application layer, where users rely on Remote Procedure Call (RPC) services under the false premise of pseudonymity. The proposed breakthrough is a passive deanonymization attack that exploits the temporal correlation between a user’s network-layer TCP packet timestamp for a transaction status query and the transaction’s public, on-chain confirmation timestamp. This reveals a fundamental, systemic vulnerability in the standard client-to-node communication model, achieving a high success rate and demonstrating that network-level privacy is a critical, unsolved challenge for all major public ledgers.
Context
Prior to this analysis, the primary focus for blockchain privacy was on cryptographic solutions like zero-knowledge proofs or mixing services, assuming the network layer provided a baseline of anonymity through IP obfuscation or the use of public RPC endpoints. The prevailing theoretical limitation centered on costly, active attacks that required transaction fees or direct man-in-the-middle positioning. The foundational challenge remained ∞ formally quantifying the leakage of user identity when a pseudonym (wallet address) interacts with a public ledger via common, latency-sensitive network infrastructure.
Analysis
The core mechanism operates by establishing a cryptographic link between two distinct, time-stamped events. The attacker, positioned as a passive observer on the network backbone, monitors a user’s IP address and records the precise time a TCP packet is sent to an RPC node to check a transaction’s status. Concurrently, the attacker monitors the public blockchain to record the transaction’s final, immutable confirmation timestamp.
The extremely narrow and unique time window, or temporal signature , between the on-chain event and the subsequent off-chain query serves as a unique identifier. This correlation is robust because the latency is a near-constant for a specific user-to-node path, allowing the attacker to link the network-layer source (IP) to the application-layer identity (pseudonym) with high certainty.
Parameters
- Success Rate Against Normal Users ∞ Over 95%. Explanation: The measured efficacy of the attack against typical users on networks like Ethereum, Bitcoin, and Solana.
- Transaction Fee Requirement ∞ Zero. Explanation: The attack is passive and does not require the adversary to submit or pay for any transactions.
- Adversary Model ∞ Strong Passive. Explanation: Assumes the attacker has access to network infrastructure like border routers but does not actively interfere with traffic.
Outlook
The immediate strategic outlook requires a fundamental re-evaluation of client-node communication protocols, prioritizing network-layer privacy primitives. Future research must focus on integrating verifiable delay functions or time-randomization techniques into RPC query responses to break the temporal signature correlation. The long-term implication is the necessity of a “Privacy-by-Default” network architecture, potentially utilizing decentralized, zero-knowledge-enabled RPC relays or fully private transaction mempools to decouple the user’s physical location from their on-chain activity.
Verdict
This research delivers a decisive, empirical demonstration that the fundamental assumption of network-layer privacy for blockchain users is invalid, necessitating a new generation of privacy-preserving communication standards.
