Payment by mobile phone will be common in the near future. Security of the payment system will partly be based on secure identification, and it will be crucial that no secret-key material, like a PIN or a password, is leaked while interacting with the payment terminal. Niek Bouman of Centrum Wiskunde & Informatica (CWI) in Amsterdam has investigated a new identification method based on quantum mechanics. This method can in principle be applied in a future generation of high security mobile payment technology. On 18 december 2012, Bouman defends his thesis at the Mathematical Institute of Leiden University.
Bouman investigates how secure two-party computation (secure 2PC) can be based on quantum mechanics. In secure 2PC, two parties perform a joint computation on their individual inputs, in such a way that they both learn the result of the computation, but the two individual inputs remain private. Identification with a password is an example of secure 2PC. Here, two parties (for instance in the form of a mobile phone and a payment terminal) each hold a password, and they want to verify whether the two passwords are identical. But since either of them could be under the control of an attacker intending to steal the password, the other party needs assurance that his password is not revealed in the process.
The security of previous proposals based on quantum mechanics relies on the technological hardness of reliably storing large quantum states. The new identification scheme developed by Bouman and his collaborators goes further: “Here, the attacker not only has to store a large quantum state in order to break the scheme, but additionally, he needs to perform so-called coherent quantum operations on the quantum state. This is something that is out of reach with current technology."
The research was conducted in CWI’s Cryptology group. This group, headed by Prof. dr. Ronald Cramer, investigates fundamental questions about cryptography from a broad scientific perspective, particularly from mathematics, computer science and physics. The reseach project was funded by dr. Serge Fehr's Vrije Competitie grant "Quantum Cryptography", awarded by the Netherlands Organisation for Scientific Research (NWO).
Thesis: Cryptography from Quantum Uncertainty, in the Presence of Quantum Side Information
By: Niek Bouman (CWI's Cryptology group)
Promotor: Prof. dr. Ronald Cramer
Co-promotor: Dr. Serge Fehr
Date: December, 18, 2012, 10.00h
Place: Leiden University, Senaatskamer Academiegebouw
More information:
• website Niek Bouman
• website Ronald Cramer
• website Serge Fehr
• website CWI Cryptology group
See also:
Nature does not allow secure computation between rivals
