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Quantum Fingerprinting
Quantum fingerprinting is a proposed technique that uses a quantum computer to generate a string with a similar function to the cryptographic hash function. Alice and Bob hold n-bit strings x and y. Their goal and a referee's is to obtain the correct value of f(x,y) = \begin 1 & \text x = y, \\ 0 & \text x \neq y. \\ \end. To do this, 2^ quantum states are produced from the O(logn)-qubit state fingerprints and sent to the referee who performs the Swap test to detect if the fingerprints are similar or different with a high probability. If unconditional guarantees of security are needed, and if it is impractical for the communicating parties to arrange to share a secret that can be used in a Carter–Wegman MAC, this technique might one day be faster than classical techniques given a quantum computer with 5 to 10 qubits. However, these circumstances are very unusual and it is unlikely the technique will ever have a practical application; it is largely of theoretical interest. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Computer
A quantum computer is a computer that exploits quantum mechanical phenomena. On small scales, physical matter exhibits properties of both particles and waves, and quantum computing takes advantage of this behavior using specialized hardware. Classical physics cannot explain the operation of these quantum devices, and a scalable quantum computer could perform some calculations exponentially faster than any modern "classical" computer. Theoretically a large-scale quantum computer could break some widely used encryption schemes and aid physicists in performing physical simulations; however, the current state of the art is largely experimental and impractical, with several obstacles to useful applications. The basic unit of information in quantum computing, the qubit (or "quantum bit"), serves the same function as the bit in classical computing. However, unlike a classical bit, which can be in one of two states (a binary), a qubit can exist in a superposition of its two " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic Hash Function
A cryptographic hash function (CHF) is a hash algorithm (a map (mathematics), map of an arbitrary binary string to a binary string with a fixed size of n bits) that has special properties desirable for a cryptography, cryptographic application: * the probability of a particular n-bit output result (hash value) for a random input string ("message") is 2^ (as for any good hash), so the hash value can be used as a representative of the message; * finding an input string that matches a given hash value (a ''pre-image'') is infeasible, ''assuming all input strings are equally likely.'' The ''resistance'' to such search is quantified as security strength: a cryptographic hash with n bits of hash value is expected to have a ''preimage resistance'' strength of n bits, unless the space of possible input values is significantly smaller than 2^ (a practical example can be found in ); * a ''second preimage'' resistance strength, with the same expectations, refers to a similar problem of f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Swap Test
The swap test is a procedure in quantum computation that is used to check how much two quantum states differ, appearing first in the work of Barenco et al. and later rediscovered by Harry Buhrman, Richard Cleve, John Watrous, and Ronald de Wolf. It appears commonly in quantum machine learning, and is a circuit used for proofs-of-concept in implementations of quantum computers. Formally, the swap test takes two input states , \phi\rangle and , \psi\rangle and outputs a Bernoulli random variable that is 1 with probability \textstyle\frac - \frac ^2 (where the expressions here use bra–ket notation). This allows one to, for example, estimate the squared inner product between the two states, ^2, to \varepsilon additive error by taking the average over O(\textstyle\frac) runs of the swap test. This requires O(\textstyle\frac) copies of the input states. The squared inner product roughly measures "overlap" between the two states, and can be used in linear-algebraic applications, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Harry Buhrman
Harry Buhrman (born 1966) is a Dutch computer scientist, currently Chief Scientist Quantum Algorithms & Innovation at Quantinuum. He previously was ''Professor of algorithms, complexity theory, and quantum computing'' at the University of Amsterdam (UvA), group leader of the Quantum Computing Group at the Centrum Wiskunde & Informatica (CWI), and executive director of QuSoft, the Dutch research center for quantum software. Buhrman research interests are on Quantum Computing, Quantum Information, Quantum Cryptography, Computational complexity theory, Kolmogorov Complexity, and Computational Biology. Buhrman contributed substantially to the quantum analogue of Communication complexity, exhibiting an advantage of the use of qubits in distributed information-processing tasks. Although quantum entanglement cannot be used to replace communication, can be used to reduce the communication exponentially. Buhrman was elected a member of the Royal Netherlands Academy of Arts and Sciences ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Richard Cleve
Richard Erwin Cleve is a Canadian professor of computer science at the David R. Cheriton School of Computer Science at the University of Waterloo, where he holds the Institute for Quantum Computing Chair in quantum computing, and an associate member of the Perimeter Institute for Theoretical Physics.Richard Cleve at the IQC directory. Education He obtained his BMath and from the University of Waterloo, and his Ph.D. in 1989 at the |
John Watrous (computer Scientist)
John Harrison Watrous is the Technical Director of IBM Quantum Education at IBM and was a professor of computer science at the David R. Cheriton School of Computer Science at the University of Waterloo, a member of the Institute for Quantum Computing, an affiliate member of the Perimeter Institute for Theoretical Physics and a Fellow of the Canadian Institute for Advanced Research.John Watrous at the Canadian Institute for Advanced Research website. He was a faculty member in the Department of Computer Science at the from 2002 to 2006 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ronald De Wolf
Ronald Michiel de Wolf (born 1973) is a Dutch Computer Scientist, currently a Senior Researcher at Centrum Wiskunde & Informatica (CWI) and a professor at the Institute for Logic, Language and Computation (ILLC) of the University of Amsterdam (UvA). His research interests are on Quantum computing, Quantum information, Coding theory, and Computational complexity theory. His scientific contributions include the first exponential separation between one-way quantum and classical communication protocols for a partial Boolean function, and a proof that a locally decodable code (LDC) with 2 classical queries need exponential length. This suggested the use of techniques from quantum computing to prove results in "classical" computer science. De Wolf and his coauthors received the Best Paper Award at the Annual ACM Symposium on Theory of Computing (STOC) in 2012. For the same article, they also received the 2022 STOC 10-year test of time award and the 2023 Gödel Prize.https://eatcs.org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qubit
In quantum computing, a qubit () or quantum bit is a basic unit of quantum information—the quantum version of the classic binary bit physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, one of the simplest quantum systems displaying the peculiarity of quantum mechanics. Examples include the spin of the electron in which the two levels can be taken as spin up and spin down; or the polarization of a single photon in which the two spin states (left-handed and the right-handed circular polarization) can also be measured as horizontal and vertical linear polarization. In a classical system, a bit would have to be in one state or the other. However, quantum mechanics allows the qubit to be in a coherent superposition of multiple states simultaneously, a property that is fundamental to quantum mechanics and quantum computing. Etymology The coining of the term ''qubit'' is attributed to Benjamin Schumacher. In the acknow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Cryptography
Quantum cryptography is the science of exploiting quantum mechanical properties to perform cryptographic tasks. The best known example of quantum cryptography is quantum key distribution, which offers an information-theoretically secure solution to the key exchange problem. The advantage of quantum cryptography lies in the fact that it allows the completion of various cryptographic tasks that are proven or conjectured to be impossible using only classical (i.e. non-quantum) communication. For example, it is impossible to copy data encoded in a quantum state. If one attempts to read the encoded data, the quantum state will be changed due to wave function collapse ( no-cloning theorem). This could be used to detect eavesdropping in quantum key distribution (QKD). History In the early 1970s, Stephen Wiesner, then at Columbia University in New York, introduced the concept of quantum conjugate coding. His seminal paper titled "Conjugate Coding" was rejected by the IEEE Informa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Digital Signature
A Quantum Digital Signature (QDS) refers to the quantum mechanical equivalent of either a classical digital signature or, more generally, a handwritten signature on a paper document. Like a handwritten signature, a digital signature is used to protect a document, such as a digital contract, against forgery by another party or by one of the participating parties. As e-commerce has become more important in society, the need to certify the origin of exchanged information has arisen. Modern digital signatures enhance security based on the difficulty of solving a mathematical problem, such as finding the factors of large numbers (as used in the RSA algorithm). Unfortunately, the task of solving these problems becomes feasible when a quantum computer is available (see Shor's algorithm). To face this new problem, new quantum digital signature schemes are in development to provide protection against tampering, even from parties in possession of quantum computers and using powerful quantum c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptographic Hash Functions
A cryptographic hash function (CHF) is a hash algorithm (a map of an arbitrary binary string to a binary string with a fixed size of n bits) that has special properties desirable for a cryptographic application: * the probability of a particular n-bit output result (hash value) for a random input string ("message") is 2^ (as for any good hash), so the hash value can be used as a representative of the message; * finding an input string that matches a given hash value (a ''pre-image'') is infeasible, ''assuming all input strings are equally likely.'' The ''resistance'' to such search is quantified as security strength: a cryptographic hash with n bits of hash value is expected to have a ''preimage resistance'' strength of n bits, unless the space of possible input values is significantly smaller than 2^ (a practical example can be found in ); * a ''second preimage'' resistance strength, with the same expectations, refers to a similar problem of finding a second message that mat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
