Existing quantum languages force the programmer to work at a low level of abstraction
leading to unintuitive and cluttered code. A fundamental reason is that dropping temporary …

These are lecture notes from a weeklong course in quantum complexity theory taught at the
Bellairs Research Institute in Barbados, February 21-25, 2016. The focus is quantum circuit …

Quantum cheques could be a forgery-free way to make transaction in a quantum networked
banking system with perfect security against any no-signalling adversary. Here, we …

Private quantum money allows a bank to mint quantum money states that it can later verify,
but that no one else can forge. In classically verifiable quantum money--introduced by …

The digital currency Bitcoin has had remarkable growth since it was first proposed in 2008.
Its distributed nature allows currency transactions without a central authority by using …

Research on quantum technology spans multiple disciplines: physics, computer science,
engineering, and mathematics. The objective of this chapter is to provide an accessible …

Inspired by the Elitzur-Vaidman bomb testing problem [arXiv: hep-th/9305002], we introduce
a new query complexity model, which we call bomb query complexity $ B (f) $. We …

We propose the idea of a quantum cheque scheme, a cryptographic protocol in which any
legitimate client of a trusted bank can issue a cheque, that cannot be counterfeited or altered …

We present a family of quantum money schemes with classical verification which display a
number of benefits over previous proposals. Our schemes are based on hidden matching …

The no-cloning property of quantum mechanics allows unforgeability of quantum banknotes
and credit cards. Quantum credit card protocols involve a bank, a client, and a payment …