National Institute of Standards and Technology における超伝導研究及び生活

Genetic programming (GP) is a systematic, domain-independent method for getting computers to solve problems automatically starting from a high-level statement of what needs to be done. Using ideas from natural evolution, GP starts from an ooze of random computer programs, and progressively refines them through processes of mutation and sexual recombination, until high-fitness solutions emerge. All this without the user having to know or specify the form or structure of solutions in advance. GP has generated a plethora of human-competitive results and applications, including novel scientific discoveries and patentable inventions. This unique overview of this exciting technique is written by three of the most active scientists in GP. See www.gp-field-guide.org.uk for more information on the book.

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A Field Guide to Genetic Programming

This paper proposes a novel evolutionary algorithm inspired by quantum computing, called a quantum-inspired evolutionary algorithm (QEA), which is based on the concept and principles of quantum computing, such as a quantum bit and superposition of states. Like other evolutionary algorithms, QEA is also characterized by the representation of the individual, evaluation function, and population dynamics. However, instead of binary, numeric, or symbolic representation, QEA uses a Q-bit, defined as the smallest unit of information, for the probabilistic representation and a Q-bit individual as a string of Q-bits. A Q-gate is introduced as a variation operator to drive the individuals toward better solutions. To demonstrate its effectiveness and applicability, experiments were carried out on the knapsack problem, which is a well-known combinatorial optimization problem. The results show that QEA performs well, even with a small population, without premature convergence as compared to the conventional genetic algorithm.

Quantum-inspired evolutionary algorithm for a class of combinatorial optimization

Smart contracts are computer programs that can be correctly executed by a network of mutually distrusting nodes, without the need of an external trusted authority. Since smart contracts handle and transfer assets of considerable value, besides their correct execution it is also crucial that their implementation is secure against attacks which aim at stealing or tampering the assets. We study this problem in Ethereum, the most well-known and used framework for smart contracts so far. We analyse the security vulnerabilities of Ethereum smart contracts, providing a taxonomy of common programming pitfalls which may lead to vulnerabilities. We show a series of attacks which exploit these vulnerabilities, allowing an adversary to steal money or cause other damage.

A Survey of Attacks on Ethereum Smart Contracts SoK

Twenty-five years ago, as an American GP living and practising in Wales, I would watch BBC sports programmes, such as darts and bowls and snooker, all unknown to me and, therefore, fascinating. I always found it odd — pairings such as Scotland (or Wales) versus The Rest of the World. It either seemed overly ambitious for Scotland or slim pickings for the rest of the world. After the recent US presidential election, it appears as if it will continue to be the US versus The Rest of the World.

Three books might help you, who are of ‘the rest of the world’, begin to grapple with what is going on in the US. Written from the short, medium, and long view, each has a somewhat parochial twist. Each also, however, contains a great deal of useful history.

The 9/11 Commission Report refutes the old saw that nothing good can be written by a committee. The report is a remarkable book and its recent nomination as a finalist for the National Book Award is a first for a government document, and well deserved. What is contained in this report is well known by most of us — the cast of characters has been in the news for over 3 years. And the sequence of events and many of the details that were gleaned from the ongoing hearings have been contained in news stories, long and short. However, to have published what is known until this point in a single narrative, which is at once accessible and clearly written, is a truly historical achievement. Reading the events of the day — regarding the planes that crashed in the city of New York, as the rescue squads from police and fire departments move into place and act — is both familiar and detailed in a way that helps us understand better than I would ever have imagined the why and how of all the death and destruction.

So much about those days have been parsed into documentaries — long analyses of causation of issues, like why the towers fell — that one would think that everything that could be written had been. But the Commission's report really does add enormous amounts of history to the sound bites and 30-second visuals that have pervaded politics and the world assessment of the US since that time. The report deals extensively and thoughtfully with the history of Islam, both ancient and recent, and describes the history of terrorism as it evolved from highjackings of the 1970s to the use of bombs and targeted destruction of military targets in the late 1980s and 1990s.

Events that occurred in the time that preceded the attacks of 9/11 are written in a way that shows the convergence of intelligence reports, a long history of threats from Bin Laden, and many alerts and warnings (‘the system was blinking red’ in the words of Tenet, CIA director). The information about the movements of the terrorists in their planning and the worldwide involvement of cells, support systems, and finances makes it clear that these events were truly the result of a network that reaches virtually everywhere.

After the attacks, reading of the efforts of the fire, police, and other rescue squads in New York adds specifics that are terrible and remarkable. On 9/11, I ran up and down the stairs between patients to watch on television as it was all happening. All of us who watched that day wondered what those people who were clearly doomed were thinking, feeling, and seeing. Their actual words in this report are not fiction, they are the words, for most the last words, of people who died as we watched. Their words are the hardest part of this long, detailed report to deal with.

Much of the final third of the report is devoted to what a fire captain friend of mine once called a PFE — a post-fire evaluation — which he mandated for his squad after every fire. In a PFE, the entire squad reconstructed, relived, and discussed the events to see what could be improved next time. The 9/11 Commission engaged in a world-scale PFE. Although all US politicians state that they intend to follow the recommendations of The 9/11 Commission Report, the backing and filling is already well underway. What politician, for example, is going to agree that major conurbations, and political and tactical targets should receive preference over their hometown fire departments and that homeland security money should ‘not be used as a pork barrel’?

Rather than bringing a grieving country together in a way that will make such events unlikely to happen again, the reactions from the report have begun to cleave along party lines once again. The 9/11 Commission was almost unique in its thoroughness, transparency, and its ability to focus on the real issue of terror and lawlessness. However, the extent to which a violent stateless ideology has negatively affected the tolerance of differences, the sense of community, and the level of civic discourse in the US means that terrorism has affected our neighborhoods as much as it has affected our country. And fear rather than determination, despite the President's stump speech, has become the dominant emotion.

Robert Byrd, from his 45-year perspective in the US Senate, understands that cheques and balances are essential to avoid tragedy, even if they, at times, impede progress. His book, Losing America, contains several ‘under-the-table’ looks at Congress and the manipulations and arrogance of the coterie of ideologues who surround George W. Bush. Byrd, from the Southern tradition of politeness and respect, which often cloaks bar-room politics, is steeped in the history of the institution of the Senate. He is personally offended by Bush's lack of interest or curiosity in the legislative process prior to 9/11, and his dishonesty and deception afterwards. Byrd's address to the Senate on the eve of the war on Iraq was widely quoted and is contained in this book. While people marching in the streets made headlines, it was an 85-year-old senator, not previously known as an outraged progressive, who took on both the Administration for its hypocrisy and many of his colleagues for their lack of courage and principle. He voted against the war and continues to point out the dishonesty of the people who guide it. The book reads with a sensibility from another age. Although his own history is certainly not without problems, Senator Byrd's belief in the true democratic process, rather than the gun-barrel approach of George W. Bush, should be given the respect that he, and it, deserve.

Arthur Schlesinger Jr has been writing history since 1946 and has Pulitzer prizes to prove he does it well. His voice is considered, thoughtful, and scholarly — as one might expect from a historian and distinguished teacher. Toward the end of his book War and the American Presidency, however, Schlesinger's voice rises with outrage at those who surround and influence George W. Bush, the ‘small group of Messianic statesman whose self righteousness bids fair to wreck our age’. He writes of the imperial presidencies of the early years of the country, which repressed dissent during wartime, and how the US moved from wars based on pique to engaging international diplomacy and internationalism. Schlesinger reminds us that all presidents since Wilson, with George W. Bush being the glaring exception, believed in statesmanship, diplomacy, alliances to guard against capricious choices and, when necessary, taking on common enemies.

Much of Schlesinger's book, however, also chronicles the record of the current Administration which, by being ‘judge, jury, and executioner resurrects the imperial presidency’. An imperial presidency in the age of frigates and single-shot rifles cannot be compared with one that possesses weapons of mass destruction and a wooly-headed sense of divine guidance. We used to think of Henry Kissinger as the prototype for Dr Strangelove, but I wish Kubrick were still alive to do the remake with Dick Cheney and Donald Rumsfeld in mind.

Needless to say, the recent election, instead of relegating George W. Bush and his hangers-on to the historical trashbin, has pushed them to the front of the international agenda. A secretive, defensive, unreflective president will now shape the world for our grandchildren. Each of these books elaborates on the ineffectiveness of Bush dealing with the real enemy while he digs deeper into a country where he is creating more enemies by the day.

One has to ask why, instead of quietly writing their memoirs, two distinguished 87-year-old statesmen are raising the alarm and shaking us by the throat — like the aging Thomas Jefferson who, in his famous letter of 1820, said of the first compromise to try to divide the country between slave and free states: ‘this momentous question, like a firebell in the night, awakened and filled me with terror’. Byrd and Schlesinger hear the firebell and are ringing it to wake us up. Another quote that might better capture Bush and his legacy would be from the Bible he uses as justification for his policies: ‘He that troubleth his own house shall inherit the wind’ (Proverbs 11, 29).

The 9/11 Commission Report: Final Report of the National Commission on Terrorist attacks upon the United States.

Formal security policies are extremely useful for two related reasons. First, they allow a policy to be considered in isolation, separate from programs under the purview of the policy and separate from the implementation of the policy’s enforcement. Second, policies can be checked for compliance against higher-level security goals by using automated analyses. By contrast, ad hoc enforcement mechanisms (for which no separate policies are specified) enjoy neither benefit, and non-formal policies enjoy the first but not the second. We would like to understand how best to define (and enforce) multi-level security policies when information must be shared across domains that have varying levels of trust (the so-called “cross domain” problem). Because we wish to show such policies meet higher-level security goals with high assurance, we are interested in specifying cross domain policies formally, and then reasoning about them using automated tools. In this report, we briefly survey work that presents formal security policies with crossdomain concerns, in particular with respect to the problem of downgrading. We also describe correctness properties for such policies, all based on noninterference. Finally, we briefly discuss recently-developed tools for analyzing formal security policies; though no existing tools focus on the analysis of downgradingoriented policies, existing research points the way to providing such support.

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Toward Specifying and Validating Cross-Domain Policies

Secure multi-party computation (MPC) enables a set of mutually distrusting parties to cooperatively compute, using a cryptographic protocol, a function over their private data. This paper presents Wys*, a new domain-specific language (DSL) for writing mixed-mode MPCs. Wys* is an embedded DSL hosted in F*, a verification-oriented, effectful programming language. Wys* source programs are essentially F* programs written in a custom MPC effect, meaning that the programmers can use F*'s logic to verify the correctness and security properties of their programs. To reason about the distributed runtime semantics of these programs, we formalize a deep embedding of Wys*, also in F*. We mechanize the necessary metatheory to prove that the properties verified for the Wys* source programs carry over to the distributed, multi-party semantics. Finally, we use F*'s extraction to extract an interpreter that we have proved matches this semantics, yielding a partially verified implementation. Wys* is the first DSL to enable formal verification of MPC programs. We have implemented several MPC protocols in Wys*, including private set intersection, joint median, and an MPC card dealing application, and have verified their correctness and security.

WYS*: A DSL for Verified Secure Multi-party Computations

Verification tools for effectful programming languages often rely on automated theorem provers such as SMT solvers to discharge their proof obligations, usually with very limited facilities for user interaction. When the need arises for logics (e.g., higher order or separation logic) or theories (e.g., non-linear arithmetic) that are hard for SMT solvers to efficiently automate, this style of program verification becomes problematic. 
Building on ideas from the interactive theorem proving community we introduce Meta-F*, a metaprogramming framework for the F* effectful language and SMT-based program verification tool. Meta-F* allows developers to write effectful metaprograms suitable for proof scripting, user-defined proof automation, and verified program construction and transformation. Metaprograms are effectful programs in F* itself, making good use of F*'s libraries, IDE support, and extraction to efficient native code. Meta-F*, moreover, is well-integrated with F*'s weakest precondition calculus and can solve or pre-process parts of the verification condition while leaving the rest for the SMT solver. 
We evaluate Meta-F* on a variety of examples, demonstrating that tactics, and metaprogramming in general, improve proof stability and automation in F*. Using metaprogrammed decision procedures for richer logics in combination with SMT solving makes it practical to apply F* in settings that were previously out of reach, such as separation logic, or that suffered from poor automation, such as the non-linear arithmetic proofs needed for verifying cryptographic primitives.

Meta-F*: Metaprogramming and Tactics in an Effectful Program Verifier.

De Bruijn graphs possess many characteristics that make them a suitable choice for the topology of an overlay network. These include constant degree at each node, logarithmic diameter and a highly-regular topology that permits nodes to make strong assumptions about the global structure of the network. We propose a distributed protocol that constructs an approximation of a de Bruijn graph in the presence of an arbitrary number of nodes. We show that the degree of each node is constant and that the diameter of the network is no worse than 2logN , where N is the number of nodes. The cost of the join and the departure procedures are O(logN) in the worst case. To the best of our knowledge, this is the first distributed protocol that provides such deterministic

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A Distributed Algorithm for Constructing a Generalization of de Bruijn Graphs

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Nikhil Swamy

Papers

Toward Specifying and Validating Cross-Domain Policies

WYS*: A DSL for Verified Secure Multi-party Computations

Meta-F*: Metaprogramming and Tactics in an Effectful Program Verifier.

A Distributed Algorithm for Constructing a Generalization of de Bruijn Graphs

Implementing and Proving the TLS 1.3 Record Layer.