Blockchain Papers

Wellner, Ingrid

No abstract is available for this record.

Cynthia Dwork, Larry Stockmeyer

No abstract is available for this record.

Jørgen Brandt, Ivan Damgård, Peter Landrock, Torben Pedersen

No abstract is available for this record.

Joan Boyar, Stuart A. Kurtz, Mark W. Krentel

No abstract is available for this record.

Alfredo De Santis, Silvio Micali, Giuseppe Persiano

No abstract is available for this record.

Mike Burmester

No abstract is available for this record.

Mihir Bellare, Silvio Micali, Rafail Ostrovsky

Quadratic residuosity and graph isomorphism are classic problems and the canonical examples of zero-knowledge languages. However, despite much research effort, all previous zero-knowledge proofs for them required either unproven complexity assumptions or an unbounded number of rounds of message exchange.

Moni Naor, Moti Yung

We show how to construct a public-key cryptosystem (as originally defined by DiNe and Hellman) secure against chosen ciphertezt attacks, given a public-key cryptosystern secure against passive eavesdropping and a noninteractive zero-knowledge proof system in the shared string model. No such secure cryptosystems were known before. A concrete implementation can be based on quadratic residuosity intractability.

Michael Ben-Or, Oded Goldreich, Shafi Goldwasser, Johan Håstad · 7 authors

No abstract is available for this record.

Alfredo De Santis, Silvio Micali, Giuseppe Persiano

No abstract is available for this record.

Oded Goldreich, Eyal Kushilevitz

No abstract is available for this record.

Uriel Feige, Dror Lapidot, Adi Shamir

In the present study, we investigated how the symmetry/asymmetry of cell division in mitotic CD34(+) cells can be evaluated by determining the plane of cell division and the potential distribution of proteins between daughter cells. The orientation of the mitotic spindle is dependent upon the positioning of the centrosomes, which determine the plane of cell division and the sharing of proteins. If the functions of unequally shared proteins are relevant to the kinetics of cell division, they could determine whether the daughter cells undergo self-renewal or differentiation. The kinetic function of the proteins of interest was investigated using a colony-replating assay and carboxyfluorescein succinimidyl ester (CFSE) staining. We used Notch/Numb as a model system, since they have a role in balancing symmetric/asymmetric divisions. Mitotic cells were examined microscopically and centrosomal markers γ-tubulin/pericentrin were used with activated Notch-1 and Numb. We monitored the first crucial divisions by CFSE staining and found an inverse relationship between activated Notch and Numb expression, suggesting a reciprocal regulation. We suggest that the subpopulations expressing activated Notch or Numb have different cell fates. To determine the influence of Notch signaling on progenitor cell self-renewal, we used the γ-secretase inhibitor N-[N-(3,5-Difluorophenacetyl-L-alanyl)]-S-phenylglycine t-Butyl ester (DAPT). DAPT influences self-renewal/differentiation outcome by affecting the frequency of symmetric renewal divisions without affecting the rate of divisions. Overall, the purpose of this study was to establish a cellular system for predicting the symmetry/asymmetry of hematopoietic progenitor divisions at the level of centrosomes and protein distribution and to investigate the influence of these proteins on progenitor cell kinetics.

Mike Burmester, Yvo Desmedt

The proof of soundness for many zero-knowledge schemes has been given in an incomplete way. We discuss the consequences.

Joe Kilian, Silvio Micali, Rafail Ostrovsky

No abstract is available for this record.

Roméo Ortega, Gustavo Sanchez Galindo

A complete proof is given of global convergence to zero of the prediction error and asymptotic optimality for a direct adaptive controller is established based on multistep quadratic cost minimization with a receding horizon philosophy. The only substantial assumptions are that the controller designed when the parameters are known, stabilizes the plant and the exact knowledge of the first N y (N y -optimization horizon) impulse response coefficients of the plant. The technical hurdles for the development of a comprehensive convergence theory of this type of controller are also highlighted.

Gilles Brassard, Claude Crépeau, Moti Yung

No abstract is available for this record.

Lance Fortnow

In 1985, Goldwasser, Micali and Rackoff formulated interactive proof systems as a tool for developing cryptographic protocols. Indeed, many exciting cryptographic results followed from studying interactive proof systems and the related concept of zero-knowledge. Interactive proof systems also have an important part in complexity theory merging the well established concepts of probabilistic and nondeterministic computation. This thesis will study the complexity of various models of interactive proof systems. A perfect zero-knowledge interactive protocol convinces a verifier that a string is in a language without revealing any additional knowledge in an information theoretic sense. This thesis will show that for any language that has a perfect zero-knowledge proof system, its complement has a short interactive protocol. This result implies that there are not any perfect zero-knowledge protocols for NP-complete languages unless the polynomial-time hierarchy collapses. Thus knowledge comp...

Joe Kilian, Silvio Micali, Rafail Ostrovsky

No abstract is available for this record.

Joe Kilian, Silvio Micali, Rafail Ostrovsky

Several resources relating to zero-knowledge protocols are considered. They are the number of envelopes used in the protocol, the number of oblivious transfer protocols executed during the protocol, and the total amount of communication required by the protocol. It is shown that after a preprocessing stage consisting of O(k) executions of oblivious transfer, any polynomial number of NP-theorems of any polysize can be proved noninteractively and in zero knowledge, on the basis of the existence of any one-way function, so that the probability of accepting a false theorem is less than 1/2/sup k/.>

和夫 太田

No abstract is available for this record.

Sarit Kraus, Daniel Lehmann

No abstract is available for this record.

Martin Tompa

Suppose an associate handed you a 500 digit number N, and informed you, know the prime factorization of N. What would convince you of the truth of your associate's statement? If your associate could be persuaded to reveal the factorization to you, a few simple tests would convince you of the statement's truth. Unfortunately the associate responds to this request by saying, factorization is a secret. In fact, I would like to convince you that I know the factorization of N without divulging any other useful information. How can you hope to be convinced that your associate is not deceiving you? Needless to say, a primality testing algorithm quickly reveals N to be composite, but your favorite factorization algorithms make no progress whatever. These seemingly irreconcilable positions (the associate's unwillingness to reveal any knowledge, your unwillingness to accept your associate's statement without proof) are reconcilable through a protocol known as a zero interactive proof, introduced by Goldwasser, Micali, and Rackoff [15] in 1985. Informally, an interactive proof is a pair of protocols executed by two parties, called the and the whereby the prover attempts to convince the verifier of the validity of some proposition II. The prover, even by deviating from its protocol, should not be able to convince the verifier of the truth of II if, in fact, II is false. An interactive proof is zero knowledge if the verifier, even by deviating from its protocol, cannot gain any information from the prover (other than the validity of II) that it could not have derived efficiently itself. More specifically, for any verifier that outputs after interacting with the prover, there is an algorithm that, without benefit of interacting with the prover, produces outputs from a distribution indistinguishable from that of the verifier. The interested reader can find careful definitions of these notions in [20]. The particular problem of of factorization will be left on the hook until the last section. The intervening sections contain some interesting historical digressions.

Kentaro Kizaki

No abstract is available for this record.

James Gleick

LOOKING FOR GOD'S FOOTPRINTS / James Gleick "Have you ever thought, Angelica," said Persse, "what a remarkable thing it is that the moon and the sun look to our eyes approximately the same size? . . . The odds against it happening by chance must be billions to one." "You don't think it was by chance?" "I think it's one of the great proofs of a divine creator," said Persse. "I think He had an eye for symmetry." —David Lodge, "Small World" SURE, IT'S EASY TO make fun. Our planet flies through space more smoothly than any airplane, covered with water yet never spilling a drop, so it must have had a Designer. Our eyes display too complex an architecture to be reached by random mutations, so they must have had a Biological Engineer. Our atmosphere contains just enough oxygen, just enough carbon to support life, so it must have had an Environmental Consultant. New York City offers a brilliantly conceived breeding ground for cockroaches; surely, therefore, we can deduce the existence of a cockroach deity. The so-called argument from design—from design, that is, to the existence of God—had barely been thought up before it was being satirized, and you can't always tell the serious versions from the parodies. But lately science has been upping the ante. No one cares any more that the moon is unusually large (although some have argued seriously that its tidal washing and splashing may have been a precondition for life's forward march out of the primordial oceans). Nowadays we have the incredibly well-tuned gravitational force, which, if put ever-so-slightly out of whack, would have turned the universe into a collection of red dwarf stars or blue giant stars, either way presumably inhospitable. We have the strong force in the atomic nucleus—a little stronger or a litter weaker, and stars apparently could not burn at all. The post-Big Bang expansion seems especially problematic. Nonscientists don't realize how lucky they are that the universe got bigger than a Ping Pong ball. When modern physicists and mathematicians calculate the odds against life as we know it, they no longer speak of "billions to one." They toss around numbers like IO40, or IO3"1, or ten to the ten to the thirtieth, a number that cannot even be typeset without either two levels of superscript or a universe full of zeroes. The Missouri Review · Il Certainly, for most of the last millennium, science and faith have been mortal enemies. Science explains; faith builds on the inexplicable. Certainly, amid the agnostic throng, few modern scientists talk openly about belief in God. Yet even so, as science staggers toward its Grand Unified Theory and other grails, some of its practitioners have been seeing an argument for God's existence in the esoterica of high-energy physics. They feel that somewhere in these cosmological coincidences, and also perhaps in the accumulating perfection of modern mathematics, lies the evidence of design that cannot be explained away. Perhaps, they feel, science is finally reaching a level of knowledge that will confirm God, instead of rendering Him superfluous. This is the argument that got its most vigorous and many-sided airing in John Updike's 1986 novel, Roger's Version. Though never quite so earnest, never quite so garrulous about it, some practicing scientists really do share at least a part of the feeling of Updike's pallid, pimpled antagonist, a computer scientist named Dale Köhler, that, as he says: "The most miraculous thing is happening. The physicists are getting down to the nitty-gritty, they've really just about pared things down to the ultimate details, and the last thing they ever expected to happen is happening. God is showing through." Updike's version contains its share of parody, to be sure. It also assembles the richest hodge-podge of scientific shoptalk to be found anywhere in fiction—absolutely authentic in its slangy allusions to cellular automata and fractal patterns and the Mandelbrot set. Dale Köhler knows his science, and he cannot be laughed at when he says, "They've been scraping away at physical reality all these centuries, and...