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Alexandria digital library
 Communications of the ACM
, 1995
"... We investigate definitions of and protocols for multiparty quantum computing in the scenario where the secret data are quantum systems. We work in the quantum informationtheoretic model, where no assumptions are made on the computational power of the adversary. For the slightly weaker task of veri ..."
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Cited by 36 (6 self)
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We investigate definitions of and protocols for multiparty quantum computing in the scenario where the secret data are quantum systems. We work in the quantum informationtheoretic model, where no assumptions are made on the computational power of the adversary. For the slightly weaker task of verifiable quantum secret sharing, we give a protocol which tolerates any t < n/4 cheating parties (out of n). This is shown to be optimal. We use this new tool to establish that any multiparty quantum computation can be securely performed as long as the number of dishonest players is less than n/6.
The quantum bit commitment theorem
 Foundations of Physics 31: 735–756
, 2001
"... Unconditionally secure twoparty bit commitment based solely on the principles of quantum mechanics (without exploiting special relativistic signalling constraints, or principles of general relativity or thermodynamics) has been shown to be impossible, but the claim is repeatedly challenged. The qua ..."
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Cited by 11 (4 self)
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Unconditionally secure twoparty bit commitment based solely on the principles of quantum mechanics (without exploiting special relativistic signalling constraints, or principles of general relativity or thermodynamics) has been shown to be impossible, but the claim is repeatedly challenged. The quantum bit commitment theorem is reviewed here and the central conceptual point, that an ``Einstein Podolsky Rosen' ' attack or cheating strategy can always be applied, is clarified. The question of whether following such a cheating strategy can ever be disadvantageous to the cheater is considered and answered in the negative. There is, indeed, no loophole in the theorem. 1.
Longterm security and universal composability
 Journal of Cryptology
"... Algorithmic progress and future technological advances threaten today’s cryptographic protocols. This may allow adversaries to break a protocol retrospectively by breaking the underlying complexity assumptions long after the execution of the protocol. Longterm secure protocols, protocols that after ..."
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Cited by 10 (2 self)
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Algorithmic progress and future technological advances threaten today’s cryptographic protocols. This may allow adversaries to break a protocol retrospectively by breaking the underlying complexity assumptions long after the execution of the protocol. Longterm secure protocols, protocols that after the end of the execution do not reveal any information to a then possibly unlimited adversary, could meet this threat. On the other hand, in many applications, it is necessary that a protocol is secure not only when executed alone, but within arbitrary contexts. The established notion of universal composability (UC) captures this requirement. This is the first paper to study protocols which are simultaneously longterm secure and universally composable. We show that the usual setup assumptions used for UC protocols (e.g., a common reference string) are not sufficient to achieve longterm secure and composable protocols for commitments or zeroknowledge protocols. We give practical alternatives (e.g., signature cards) to these usual setupassumptions and show that these enable the implementation of the important primitives
Alternative Computational Models: A Comparison of Biomolecular and Quantum Computation
 INVITED PAPER,18TH INTERNATIONAL CONFERENCE ON FOUNDATIONS OF SOFTWARE TECHNOLOGY AND THEORETICAL COMPUTER SCEINCE (FST&TCS98
, 1998
"... ..."
Multiparty Quantum Computation
 MASTER'S THESIS, MIT
, 2001
"... We investigate definitions of and protocols for multiparty quantum computing in the scenario where the secret data are quantum systems. We work in the quantum informationtheoretic model, where no assumptions are made on the computational power of the adversary. For the slightly weaker task of veri ..."
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Cited by 7 (1 self)
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We investigate definitions of and protocols for multiparty quantum computing in the scenario where the secret data are quantum systems. We work in the quantum informationtheoretic model, where no assumptions are made on the computational power of the adversary. For the slightly weaker task of verifiable quantum secret sharing, we give a protocol which tolerates any t < n/4 cheating parties (out of n). This is shown to be optimal. We use this new tool to establish that any multiparty quantum computation can be securely performed as long as the number of dishonest players is less than n/6.
Secure Classical Bit Commitment over Finite Channels
, 2002
"... If mistrustful parties A and B control two or more appropriately located sites, special relativity can be used to guarantee that a pair of messages exchanged by A and B are independent. Using this fact, a relativistic bit commitment protocol, RBC1, was recently defined. Security is maintained in RBC ..."
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Cited by 5 (1 self)
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If mistrustful parties A and B control two or more appropriately located sites, special relativity can be used to guarantee that a pair of messages exchanged by A and B are independent. Using this fact, a relativistic bit commitment protocol, RBC1, was recently defined. Security is maintained in RBC1 by exchanging a sequence of messages whose transmission rate increases exponentially in time. We define here a new relativistic protocol, RBC2, which requires only a constant transmission rate and could be practically implemented. We prove that RBC2 allows a bit commitment to be indefinitely maintained with unconditionally security against all classical attacks, and discuss its security against general quantum attacks.
The Security of Quantum Bit Commitment Schemes
"... Can quantum mechanics be harnessed to provide unconditionally secure bit commitment schemes and other cryptographic primitives beyond key distribution? We review the general impossibility proof of Mayers and illustrate it by showing how to break some recent attempts to bypass it. In particular, secu ..."
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Cited by 4 (0 self)
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Can quantum mechanics be harnessed to provide unconditionally secure bit commitment schemes and other cryptographic primitives beyond key distribution? We review the general impossibility proof of Mayers and illustrate it by showing how to break some recent attempts to bypass it. In particular, secure schemes would follow if we could force participants to perform measurements at specified points in the execution of the protocol. It has been suggested to use shortlived classical bit commitment schemes for this purpose. Alas, this strategy was doomed as measurements can always be postponed in an undetectable way until cheating becomes possible. It is well known that quantum mechanics can be used to allow two people to establish confidential communication under the nose of an eavesdropper equipped with unlimited computing power [1, 3, 4]. Can quantum mechanics be useful for the implementation of other cryptographic tasks? One of the most important primitives in classical cryptography is...
Quantum Information Processing: Algorithms, Technologies and Challenges
 BIOINSPIRED COMPUTING, (EDITED BY M. M. ESHAGHIANWILNER
, 2009
"... Quantum Computation (QC) is a type of computation where unitary and measurement operations are executed on linear superpositions of basis states. This paper provides a brief introduction to QC. We begin with a discussion of basic models for QC such as quantum TMs, quantum gates and circuits and rela ..."
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Cited by 3 (2 self)
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Quantum Computation (QC) is a type of computation where unitary and measurement operations are executed on linear superpositions of basis states. This paper provides a brief introduction to QC. We begin with a discussion of basic models for QC such as quantum TMs, quantum gates and circuits and related complexity results. We then discuss a number of topics in quantum information theory, including bounds for quantum communication and I/O complexity, methods for quantum data compression. and quantum error correction (that is, techniques for decreasing decoherence errors in QC), Furthermore, we enumerate a number of methodologies and technologies for doing QC. Finally, we discuss resource bounds for QC including bonds for processing time, energy and volume, particularly emphasizing challenges in determining volume bounds for observation apperatus.
On Deniability in Quantum Key Exchange
"... Abstract. We show that claims of “perfect security ” for keys produced by quantum key exchange (QKE) are limited to “privacy ” and “integrity.” Unlike a onetime pad, QKE does not necessarily enable Sender and Receiver to pretend later to have established a different key. This result is puzzling in ..."
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Cited by 2 (0 self)
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Abstract. We show that claims of “perfect security ” for keys produced by quantum key exchange (QKE) are limited to “privacy ” and “integrity.” Unlike a onetime pad, QKE does not necessarily enable Sender and Receiver to pretend later to have established a different key. This result is puzzling in light of Mayers ’ “NoGo ” theorem showing the impossibility of quantum bit commitment. But even though a simple and intuitive application of Mayers ’ protocol transformation appears sufficient to provide deniability (else QBC would be possible), we show several reasons why such conclusions are illfounded. Mayers ’ transformation arguments, while sound for QBC, are insufficient to establish deniability in QKE. Having shed light on several unadvertised pitfalls, we then provide a candidate deniable QKE protocol. This itself indicates further shortfalls in current proof techniques, including reductions that preserve privacy but fail to preserve deniability. In sum, purchasing undeniability with an offtheshelf QKE protocol is significantly more expensive and dangerous than the mere optic fiber for which “perfect security ” is advertised. 1
Implementation of a TwoState Quantum Bit Commitment Protocol in Optical Fibers
, 2015
"... We demonstrate experimentally the feasibility of a twostate quantum bit commitment protocol, which is both concealing and partially binding, assuming technological limitations. The security of this protocol is based on the lack of longterm stable quantum memories. We use a polarizationencoding ..."
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We demonstrate experimentally the feasibility of a twostate quantum bit commitment protocol, which is both concealing and partially binding, assuming technological limitations. The security of this protocol is based on the lack of longterm stable quantum memories. We use a polarizationencoding scheme and optical fiber as a quantum channel. The measurement probability for the commitment is obtained and the optimal cheating strategy demonstrated. The average success rates for an honest player in the case where the measurements are performed using equal bases are 93.4%, when the rectilinear basis is measured, and 96.7%, when the diagonal basis is measured. The rates for the case when the measurements are performed in different bases are 52.9%, when the rectilinear basis is measured, and 55.4 % when the diagonal basis is measured. The average success rates for the optimal cheating strategy are 80 % and 73.8%, which are way below the success rates of an honest player. Using a strict numerical validity criterion, we show that, for these experimental values, the protocol is secure. 1