By Zhang Tong
Chinese scientists have developed a new blockchain storage technology that they say can resist attacks from quantum computers.
Blockchain technology 鈥 which provides a shared, decentralised digital ledger that stores tamper-proof records 鈥 has shown revolutionary potential in areas like financial services and supply chain management.
Usually, blockchains use specialised encryption algorithms to verify each transaction, ensure the ledger鈥檚 security, and provide transparent access to data.
鈥淗owever, the rise of quantum computers threatens to break today鈥檚 blockchain security systems,鈥 said Wu Tong, an associate professor with the University of Science and Technology Beijing.
鈥淓ven the most advanced methods struggle against quantum attacks.鈥
Wu worked with a team from the Beijing Institute of Technology and Guilin University of Electronic Technology to find a solution to the problem.
They came up with EQAS 鈥 or efficient quantum-resistant authentication storage 鈥 which the team outlined in the Chinese-language Journal of Software in early June.
Current mainstream security methods rely on complex mathematical problems like large-number factorisation, but quantum computers can easily solve those problems using algorithms.
鈥淪pecifically, existing signature-based security becomes vulnerable under quantum attacks,鈥 Wu said. 鈥淎ttackers could forge data or insert malicious records without detection, compromising the blockchain鈥檚 integrity and consistency.鈥
She said many of the existing blockchain security technologies still relied on maths problems that were vulnerable to quantum computers.
鈥淭o ensure long-term security, we must upgrade these methods,鈥 Wu said.
The EQAS system replaces vulnerable maths-based encryption with a signature tool known as SPHINCS, which was unveiled in 2015 at an international cryptography conference. It uses quantum-resistant hash functions 鈥 or simpler maths checks 鈥 instead of complex problems.
This also simplifies device key management, avoiding synchronisation headaches 鈥 a big advantage for blockchain networks where nodes independently verify transactions.
Data storage is also separated from verification in the EQAS system. It generates proofs using a 鈥渄ynamic tree鈥 structure and then validates them using an efficient 鈥渟upertree鈥 framework.
The researchers said this approach boosted scalability and improved performance while reducing the strain on servers.
For the study, the team also put the security and efficiency of EQAS to the test. By optimising parameters it produced smaller signatures and faster verification while maintaining security.
In simulations, EQAS took about 40 seconds to complete authentication and storage tasks 鈥 much faster than the Ethereum blockchain鈥檚 current confirmation time of about 180 seconds, with 12 blocks taking 15 seconds each.
Wang Chao, a professor at Shanghai University who specialises in quantum attacks and was not involved in the study, noted that quantum attacks on blockchains were still a rarity.
鈥淚t鈥檚 like a wooden gate being vulnerable to fire. But if you replace the gate with stone, the fire becomes useless,鈥 he said. 鈥淲e need to prepare, but there is no need to panic.鈥
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