An anonymous network bandwidth measurement method and system based on blockchain technology

Abstract

This invention relates to an anonymous network bandwidth measurement method and system based on blockchain technology, belonging to the field of network information security technology. The method of this invention utilizes a distributed measurement scheme based on smart contracts and blockchain to avoid system unavailability caused by attacks on a central server. By using randomly changing measurement operators in each round, attackers find it difficult to identify specific IP addresses, reducing the risk of measurement operators suffering DoS attacks. The entry node also acts as a measurement operator; links measured by such nodes cannot distinguish between measurement links and communication links, reducing the risk of malicious nodes launching bandwidth inflation attacks, and resulting in more accurate measurement results. This invention achieves decentralized bandwidth measurement while ensuring the security and accuracy of the provided measurement results.

Description

Technical Field

[0001] This invention relates to an anonymous network bandwidth measurement method and system based on blockchain technology, belonging to the field of network information security technology. Background Technology

[0002] Anonymous networks are a technology built on the internet that provides users with privacy protection for their communications. Unlike traditional encryption technologies that only protect the confidentiality of communication content, anonymous networks combine various techniques such as message forwarding, data encryption, and traffic obfuscation to hide sensitive information such as the identity of communicating entities and communication relationships.

[0003] The Onion Network is one of the most popular anonymous communication systems on the internet. It consists of approximately 6,500 geographically dispersed repeaters operated by volunteers, transmitting a total traffic of nearly 200 Gbit / s. In recent years, with the growth in the number of users, the forwarding traffic has also increased, placing a significant burden on the Onion Network. To balance this massive traffic load, the Onion Network needs to actively measure the bandwidth performance of its nodes and guide clients to select nodes based on their bandwidth estimates.

[0004] Currently, the bandwidth measurement scheme for the Onion Anonymous Network is as follows:

[0005] The Onion Anonymous Network uses a load balancing system called TorFlow to address this issue. In the Onion Anonymous Network, the distribution of topology information relies on nine trusted directory servers (DirAuths), five of which also act as bandwidth servers (BWAuths). To ensure balanced Tor performance across all clients, the five bandwidth authorities run TorFlow using their own scanners to monitor the performance of each relay and use this value to calculate a bandwidth weight for each relay. These bandwidth weights are collected and reported to the bandwidth servers, which then vote on their collected topology information, following a consensus protocol to reach an agreement on an aggregated version of the relay information before distributing it to clients. Onion Anonymous Network clients can use these weights as probabilities when selecting relays for their paths through the network, attempting to balance user load across relays.

[0006] However, the above solution has the following technical drawbacks:

[0007] 1. Centralization of measurement scheme.

[0008] A powerful adversary could potentially compromise the directory servers, and compromising just five (out of a total of nine) could render the entire system unusable. Furthermore, if the bandwidth servers go offline, the Onion Anonymous Network will eventually revert to an equal-weighted (uniformly random) strategy, which will negatively impact client performance.

[0009] 2. Poor security.

[0010] TorFlow's measurement results are vulnerable to attack and tampering. Because the IP addresses of these bandwidth scanners are known or detectable, attackers can use IP address-based bandwidth DoS attacks to disrupt the node scanning process. A bandwidth DoS attack will block the TorFlow scanner's connection, increasing latency and packet loss on these connections, and prolonging the time it takes for the scanner to successfully complete a file download across network nodes. Therefore, an attacker could effectively manipulate the scanner to believe that the node is providing worse performance than it actually is.

[0011] 3. Low accuracy.

[0012] Because Torflow weights nodes based on their performance, attackers can effectively reduce the accuracy of node weights, potentially disrupting the load balancing process. A subtle attack exploits Torflow's two-hop measurement circuitry, known as a bandwidth inflation attack. Since measurement circuitry has fixed start and end points, it is easily identified by the relay under test. A malicious relay can then serve only the measurement circuitry, ignoring all other circuits, thus giving the server the impression of high bandwidth without incurring significant costs.

[0013] In conclusion, traditional anonymous network bandwidth measurement carries the risk of inaccurate bandwidth information, which malicious attackers may exploit to launch deanonymization attacks against users, threatening their anonymity.

[0014] Blockchain is a distributed ledger technology that uses cryptographic algorithms to ensure the immutability of data and consensus algorithms to achieve data synchronization in peer-to-peer network environments. In open network environments, blockchain-based data sharing can eliminate users' dependence on trusted central nodes, which aligns perfectly with the decentralized requirements of anonymous network bandwidth measurement.

[0015] Ethereum is currently the most widely used public blockchain, with a market capitalization of approximately $192.5 billion and over 10,000 daily active nodes. Ethereum's cryptocurrency is called Ether (ETH). Ethereum is described as a second-generation blockchain because it supports smart contracts. Smart contracts (SCs) are programs stored on the blockchain that can be invoked by sending transactions to their addresses to perform operations. Ethereum smart contracts are typically written in Solidity, and their code executes in a special environment called the Ethereum Virtual Machine (EVM). Ethereum is currently the most advanced blockchain supporting smart contracts and fully meets the needs of anonymous networks and decentralized bandwidth measurement functions.

[0016] ChainLink is a decentralized blockchain oracle network designed to securely and reliably connect blockchain smart contracts to off-chain systems. ChainLink Contract Automation reliably executes smart contract functions using time-based triggers, while ChainLink Verifiable Random Functions (VRFs) provide verifiable random numbers. ChainLink also assists smart contracts in achieving decentralized measurement processes.

[0017] To enhance the anonymity of participants in anonymous network bandwidth measurement, the selected blockchain network needs to have as many nodes as possible, while also supporting the building and deployment of decentralized applications. As executable program code, smart contracts are published in the blockchain network as transactions and are automatically triggered to execute when predetermined conditions are met. Smart contracts add programmability to the blockchain, transforming it into a programmable data-sharing platform. Summary of the Invention

[0018] The purpose of this invention is to solve the technical problem of how to securely and accurately perform distributed bandwidth measurement of network nodes in anonymous network scenarios. It creatively proposes an anonymous network bandwidth measurement method and system based on blockchain technology. This invention achieves decentralized bandwidth measurement while ensuring the security and accuracy of the provided measurement results.

[0019] The objective of this invention is achieved through the following technical solution.

[0020] An anonymous network bandwidth measurement method based on blockchain technology includes the following steps:

[0021] Step 1: Initialization.

[0022] Create a smart contract on the blockchain to store and invoke ChainLink information for surveyors. The address of this contract should be publicly available to entry nodes that wish to become surveyors, serving as a unique identifier for invoking the contract.

[0023] An anonymous network entry node aspiring to become a surveyor can read or write on-chain data by calling contract functions based on the contract address. Random number generation is automated by calling ChainLink functions.

[0024] Step 2: Node registration.

[0025] Before participating in the measurement process, entry nodes in the network must send a registration transaction signed by their wallet keys to the smart contract. The smart contract receives and stores the data in the transaction.

[0026] Step 3: Measurement preparation.

[0027] Chainlink uses two functions—Contract Automation and Verifiable Random Function (VRF)—to automatically generate a set of random numbers within a measurement cycle. At the start of each measurement cycle, the measurer queries the blockchain, and only measurers whose names match the list of random numbers are granted permission to perform the current measurement from the smart contract. Once the measurer has successfully obtained permission, they begin preparing to run the measurement scheme.

[0028] Step 4: Measurement.

[0029] Each surveyor will sort the nodes according to the bandwidth measurement information in the consensus file, select the node to be tested, and establish a measurement link with the node to be tested to perform bandwidth measurement.

[0030] Step 5: Report and aggregate the results.

[0031] After the measurement is completed, the surveyor sends the measurement results to the smart contract for aggregation via a transaction report.

[0032] The directory server calls the smart contract to read the measurement results, writes them into the consensus file, and distributes them to the clients.

[0033] Beneficial effects

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1. Decentralized Measurement Scheme. The distributed measurement scheme using smart contracts and blockchain avoids system unavailability caused by attacks on the central server.

[0036] 2. Strong security. The constantly changing surveyors in each round make it difficult for attackers to identify specific IP addresses, reducing the risk of surveyors suffering from DoS attacks.

[0037] 3. High accuracy. The entry node also acts as the measurement operator. When a measurement is initiated by such a node, the node under test cannot distinguish whether it is a measurement link or a communication link. This reduces the risk of malicious nodes launching bandwidth inflation attacks, resulting in more accurate measurement results. Attached Figure Description

[0038] Figure 1 This is a flowchart illustrating the method of the present invention.

[0039] Figure 2 This is a schematic diagram of the system architecture of the present invention. Detailed Implementation

[0040] The technical solution of the present invention will be further described clearly and completely below with reference to specific embodiments and the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0041] On the one hand, this invention proposes an anonymous network bandwidth measurement method based on blockchain technology, such as... Figure 1 As shown, it includes the following steps:

[0042] Step 1: Initialization.

[0043] Create a storage space for measurement personnel information on the blockchain and invoke ChainLink smart contracts. This contract address should be publicly available to entry nodes wishing to become measurement personnel, serving as a unique identifier for invoking the contract. Entry nodes wishing to become measurement personnel invoke contract functions based on the contract address to read and write on-chain data. ChainLink Contract Automation reliably executes smart contract functions using time-based triggers, while ChainLink Verifiable Random Functions (VRFs) provide verifiable random numbers. Therefore, these two functions are used to automatically generate a set of random numbers within a measurement cycle. This set of random numbers will be used to specify the measurement personnel participating in the measurement within the measurement cycle.

[0044] Step 2: Node registration.

[0045] To improve the feasibility of the solution, we use highly trusted entry nodes within the anonymous network as measurement operators. Before participating in the measurement process, each entry node must send a registration transaction signed by its wallet key to the smart contract. This transaction must include the node's identity information, such as its name, IP address, anonymous network identity authentication, and entry identifier. The smart contract receives and stores the data in the transaction; only the data owner (the transaction sender) can modify this information later.

[0046] Step 3: Measurement preparation.

[0047] Chainlink uses two functions—Contract Automation and Verifiable Random Function (VRF)—to automatically generate a set of random numbers within a measurement cycle. The smart contract uses these random numbers to select the measurers participating in that round of measurement. At the start of each measurement cycle, the measurer queries the blockchain and invokes the permission acquisition function. Only measurers whose names appear in the list corresponding to the random number can obtain permission from the smart contract for that round of measurement. Once the measurer successfully obtains permission, they begin preparing to run the measurement scheme.

[0048] Step 4: Measurement.

[0049] Each surveyor will sort the nodes according to the bandwidth measurement information in the consensus file and select the node to be tested. The surveyor establishes a two-hop link with the node to be tested to download the file to a pre-determined target server and performs multiple measurements on the download speed to calculate the average and median. Notably, this scheme fixes the node to be tested at the first hop and searches for a suitable node in the set of exit nodes as the second hop. The node to be tested can only know that it has joined the link as an intermediate node and cannot identify the link attributes.

[0050] Step 5: Report and aggregate the results.

[0051] After the measurement is completed, the surveyor summarizes the measurement results and sends the results transaction to the smart contract. The smart contract reads the bandwidth information from the transaction and aggregates it. The directory server calls the smart contract's query function to read the measurement results, writes them to the consensus file, and distributes them to clients.

[0052] On the other hand, this method further proposes an anonymous network bandwidth measurement system based on blockchain technology to implement the above method, such as... Figure 2 As shown, it includes: a node group consisting of decentralized blockchain network node resources, a smart contract running on each node, a ChainLink service provider, an anonymous network client, the anonymous network and its nodes, the client's target server, and a specific server used for measuring the link.

[0053] The smart contract is responsible for automatically conducting bandwidth measurements for anonymous network bandwidth measurement participants, such as reading and writing measurement participant registration information and generating random numbers. The data generated during the bandwidth measurement process is stored on various distributed blockchain nodes, making it difficult for adversaries to tamper with or forge.

[0054] To illustrate the content and implementation methods of this invention, the above specific embodiments are provided in this specification. However, those skilled in the art should understand that this invention is not limited to the above-described preferred embodiments, and anyone can derive other various forms of products under the guidance of this invention. Regardless of any changes made in their shape or structure, any technical solution that is the same as or similar to this application falls within the protection scope of this invention.

Claims

1. A method for measuring anonymous network bandwidth based on blockchain technology, characterized in that, Includes the following steps: Step 1: Initialization; Create a smart contract on the blockchain to store and call ChainLink information for surveyors. The address of this contract should be publicly available to entry nodes that want to become surveyors, serving as a unique identifier for calling the contract. An anonymous network entry node that wants to become a surveyor can read or write on-chain data by calling contract functions based on the contract address. Random number generation can be automated by calling ChainLink functions; Step 2: Node registration; Before participating in the measurement process, entry nodes in the network must send a registration transaction signed by their wallet keys to the smart contract; the smart contract receives and saves the data in the transaction. Step 3: Measurement Preparation; Chainlink has two functions—contract automation and verifiable random functions—that automatically generate a set of random numbers within a measurement period. At the start of each measurement cycle, the surveyor queries the blockchain, and only surveyors whose names appear in the list corresponding to the random number can obtain permission for this round of measurement from the smart contract. After the surveyor successfully obtains the necessary permissions, they begin preparing to run the measurement plan. Step 4: Measurement; Each measurement operator will sort the nodes according to the bandwidth measurement information in the consensus file, select the node to be measured, and establish a measurement link with the node to be measured to perform bandwidth measurement. Step 5: Report and aggregate results; After the measurement is completed, the surveyor sends the measurement results to the smart contract for aggregation via a transaction report. The directory server calls the smart contract to read the measurement results, writes them into the consensus file, and distributes them to the clients.

2. An anonymous network bandwidth measurement system based on blockchain technology that implements the method of claim 1, characterized in that, include: A node group consisting of decentralized blockchain network node resources, smart contracts running on each node, ChainLink service providers, anonymous network clients, anonymous networks and their nodes, the target server of the client, and specific servers used for measuring the link; The smart contract is responsible for automatically conducting bandwidth measurements for anonymous network bandwidth measurement participants, reading and writing measurement personnel registration information, and generating random numbers. The data generated during the bandwidth measurement process is stored in various distributed blockchain nodes, making it difficult for adversaries to tamper with or forge it.

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