Fujitsu has revealed that it has carried out several tests to evaluate the security of the RSA cryptographic system, one of the most widely used and popular, with the aim of try to discover a possible vulnerability that makes it possible for quantum computers can decipher elements encrypted with RSA.
This encryption system is based on a standard cryptographic algorithm, and offers a secure method to guarantee the confidentiality and integrity of data in digital interactions. It is used in all kinds of scenarios, including the transmission and receipt of credit card information in online purchases. The system is based on the fact that factoring a large integer is complicated.
The tests were carried out last January with a Fujitsu’s 39-qubit quantum simulator, developed in September 2022, and using a Shor algorithm to specify the resources they needed to break the encryption. The simulator harnessed the high-speed computing power of the Fugaku supercomputer’s A64FX CPU and Fujitsu’s massively parallel computing technology. With them, they therefore evaluated how complicated it would be for a quantum computer to decipher the existing RSA cryptography.
The results of these tests have shown that to crack RSA would require a fault-tolerant quantum computer with a scale of about 10,000 qubits and 2.23 trillion quantum gates. Therefore, the capabilities to break this encryption are well above those of the most advanced current quantum computers in the world. In addition, the researchers estimated that decrypting RSA requires computations that are fault-tolerant for approximately 104 days.
Since current computers can factor numbers up to 829 bits, experts believe that a cryptographic system with a key length of 2,048 bits will remain secure despite future improvements in the capabilities of quantum computers. However, concerns remain that when fault-tolerant quantum computers become available they will be able to factor even huge composite numbers, and become a potential threat to RSA cryptography.
Therefore, at some point it will be necessary to move from the RSA encryption system to alternative technologies, such as post-quantum technology. Due to the lack of tests in this regard, it is still difficult to estimate the computational resources that are needed for quantum computers to be able to truly carry out the integer factorization of numbers composed of 2,048 bits. As a consequence, the timing of when this transition to other encryption technologies should occur remains unclear.
Current quantum technology, yes, is not powerful enough to break RS.A encryption. But Fujitsu will continue to periodically and proactively evaluate the impact of this type of equipment on cryptography security, with the aim of to detect when it will be necessary to have a cryptography resistant to quantum computing.
According to Tetsuya Izu, Fujitsu Senior Director of Data Research and Securitythe investigation “It shows that quantum computing does not pose an immediate threat to existing cryptographic methods. However, we cannot rest on our laurels either. The world needs to start preparing now for the possibility that one day quantum computers could fundamentally transform the way we think about security..”
The company presented part of its test results at the Symposium on Cryptography and Information Security 2023 (SCIS 2023)which was held at the end of January in the Japanese city of Kitakyushu.