|
Michael O. Rabin
Michael Oser Rabin (; born September 1, 1931) is an Israeli mathematician, computer scientist, and recipient of the Turing Award. Biography Early life and education Rabin was born in 1931 in Breslau, Germany (today Wrocław, in Poland), the son of a rabbi. In 1935, he emigrated with his family to Mandatory Palestine. As a young boy, he was very interested in mathematics and his father sent him to the best high school in Haifa, where he studied under mathematician Elisha Netanyahu, who was then a high school teacher. Rabin graduated from the Hebrew Reali School in Haifa in 1948, and was drafted into the army during the 1948 Arab–Israeli War. The mathematician Abraham Fraenkel, who was a professor of mathematics in Jerusalem, intervened with the army command, and Rabin was discharged to study at the university in 1949. Afterwards, he received an M.Sc from Hebrew University of Jerusalem. He began graduate studies at the University of Pennsylvania before receiving a Ph.D. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infinite-tree Automaton
In computer science and mathematical logic, an infinite-tree automaton is a state machine that deals with infinite tree structures. It can be seen as an extension of top-down finite-tree automata to infinite trees or as an extension of infinite-word automata to infinite trees. A finite automaton which runs on an infinite tree was first used by Michael Rabin for proving decidability of S2S, the monadic second-order theory with two successors. It has been further observed that tree automata and logical theories are closely connected and it allows decision problems in logic to be reduced into decision problems for automata. Definition Infinite-tree automata work on \Sigma-labeled trees. There are many slightly different definitions; here is one. A (nondeterministic) infinite-tree automaton is a tuple A = (\Sigma, D, Q, q_0, \delta, F ) with the following components. * \Sigma is an alphabet. This alphabet is used to label nodes of an input tree. * D\subset \mathbb is a finite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wrocław
Wrocław is a city in southwestern Poland, and the capital of the Lower Silesian Voivodeship. It is the largest city and historical capital of the region of Silesia. It lies on the banks of the Oder River in the Silesian Lowlands of Central Europe, roughly from the Sudetes, Sudeten Mountains to the north. In 2023, the official population of Wrocław was 674,132, making it the third-largest city in Poland. The population of the Wrocław metropolitan area is around 1.25 million. Wrocław is the historical capital of Silesia and Lower Silesia. The history of the city dates back over 1,000 years; at various times, it has been part of the Kingdom of Poland, the Kingdom of Bohemia, the Kingdom of Hungary, the Habsburg monarchy of Austria, the Kingdom of Prussia and German Reich, Germany, until it became again part of Poland in 1945 immediately after World War II. Wrocław is a College town, university city with a student population of over 130,000, making it one of the most yo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rabin Cryptosystem
The Rabin cryptosystem is a family of public-key encryption schemes based on a trapdoor function whose security, like that of RSA, is related to the difficulty of integer factorization. The Rabin trapdoor function has the advantage that inverting it has been mathematically proven to be as hard as factoring integers, while there is no such proof known for the RSA trapdoor function. It has the disadvantage that each output of the Rabin function can be generated by any of four possible inputs; if each output is a ciphertext, extra complexity is required on decryption to identify which of the four possible inputs was the true plaintext. Naive attempts to work around this often either enable a chosen-ciphertext attack to recover the secret key or, by encoding redundancy in the plaintext space, invalidate the proof of security relative to factoring. Public-key encryption schemes based on the Rabin trapdoor function are used mainly for examples in textbooks. In contrast, RSA is the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Probabilistic Automaton
In mathematics and computer science, the probabilistic automaton (PA) is a generalization of the nondeterministic finite automaton; it includes the probability of a given transition into the transition function, turning it into a transition matrix. Thus, the probabilistic automaton also generalizes the concepts of a Markov chain and of a subshift of finite type. The languages recognized by probabilistic automata are called stochastic languages; these include the regular languages as a subset. The number of stochastic languages is uncountable. The concept was introduced by Michael O. Rabin in 1963; a certain special case is sometimes known as the Rabin automaton (not to be confused with the subclass of ω-automata also referred to as Rabin automata). In recent years, a variant has been formulated in terms of quantum probabilities, the quantum finite automaton. Informal Description For a given initial state and input character, a deterministic finite automaton (DFA) has exactl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oblivious Transfer
In cryptography, an oblivious transfer (OT) protocol is a type of protocol in which a sender transfers one of potentially many pieces of information to a receiver, but remains oblivious as to what piece (if any) has been transferred. The first form of oblivious transfer was introduced in 1981 by Michael O. Rabin. In this form, the sender sends a message to the receiver with probability 1/2, while the sender remains oblivious as to whether or not the receiver received the message. Rabin's oblivious transfer scheme is based on the RSA cryptosystem. A more useful form of oblivious transfer called 1–2 oblivious transfer or "1 out of 2 oblivious transfer", was developed later by Shimon Even, Oded Goldreich, and Abraham Lempel, in order to build protocols for secure multiparty computation. It is generalized to "1 out of ''n'' oblivious transfer" where the user gets exactly one database element without the server getting to know which element was queried, and without the user know ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nondeterministic Finite Automata
In automata theory, a finite-state machine is called a deterministic finite automaton (DFA), if * each of its transitions is ''uniquely'' determined by its source state and input symbol, and * reading an input symbol is required for each state transition. A nondeterministic finite automaton (NFA), or nondeterministic finite-state machine, does not need to obey these restrictions. In particular, every DFA is also an NFA. Sometimes the term NFA is used in a narrower sense, referring to an NFA that is ''not'' a DFA, but not in this article. Using the subset construction algorithm, each NFA can be translated to an equivalent DFA; i.e., a DFA recognizing the same formal language. Like DFAs, NFAs only recognize regular languages. NFAs were introduced in 1959 by Michael O. Rabin and Dana Scott, who also showed their equivalence to DFAs. NFAs are used in the implementation of regular expressions: Thompson's construction is an algorithm for compiling a regular expression to an NFA that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S2S (mathematics)
In mathematics, S2S is the monadic second order theory with two successors. It is one of the most expressive natural decidable theories known, with many decidable theories interpretable in S2S. Its decidability was proved by Rabin in 1969. Basic properties The first order objects of S2S are finite binary strings. The second order objects are arbitrary sets (or unary predicates) of finite binary strings. S2S has functions ''s''→''s''0 and ''s''→''s''1 on strings, and predicate ''s''∈''S'' (equivalently, ''S''(''s'')) meaning string ''s'' belongs to set ''S''. Some properties and conventions: * By default, lowercase letters refer to first order objects, and uppercase to second order objects. * The inclusion of sets makes S2S second order, with "monadic" indicating absence of ''k''-ary predicate variables for ''k''>1. * Concatenation of strings ''s'' and ''t'' is denoted by ''st'', and is ''not'' generally available in S2S, not even ''s''→0''s''. The prefix relation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hyper-encryption
Hyper-encryption is a form of encryption invented by Michael O. Rabin which uses a high-bandwidth source of public random bits, together with a secret key that is shared by only the sender and recipient(s) of the message. It uses the assumptions of Ueli Maurer's bounded-storage model as the basis of its secrecy. Although everyone can see the data, decryption by adversaries without the secret key is still not feasible, because of the space limitations of storing enough data to mount an attack against the system. Unlike almost all other cryptosystems except the one-time pad, hyper-encryption can be proved to be information-theoretically secure, provided the storage bound cannot be surpassed. Moreover, if the necessary public information cannot be stored at the time of transmission, the plaintext can be shown to be impossible to recover, regardless of the computational capacity available to an adversary in the future, even if they have access to the secret key at that future time. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miller–Rabin Primality Test
The Miller–Rabin primality test or Rabin–Miller primality test is a probabilistic primality test: an algorithm which determines whether a given number is likely to be prime, similar to the Fermat primality test and the Solovay–Strassen primality test. It is of historical significance in the search for a polynomial-time deterministic primality test. Its probabilistic variant remains widely used in practice, as one of the simplest and fastest tests known. Gary L. Miller discovered the test in 1976. Miller's version of the test is deterministic, but its correctness relies on the unproven extended Riemann hypothesis. Michael O. Rabin modified it to obtain an unconditional probabilistic algorithm in 1980. Mathematical concepts Similarly to the Fermat and Solovay–Strassen tests, the Miller–Rabin primality test checks whether a specific property, which is known to hold for prime values, holds for the number under testing. Strong probable primes The property is th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berlekamp–Rabin Algorithm
In number theory, Berlekamp's root finding algorithm, also called the Berlekamp–Rabin algorithm, is the probabilistic method of finding roots of polynomials over the field \mathbb F_p with p elements. The method was discovered by Elwyn Berlekamp in 1970 as an auxiliary to the algorithm for polynomial factorization over finite fields. The algorithm was later modified by Rabin for arbitrary finite fields in 1979. The method was also independently discovered before Berlekamp by other researchers. History The method was proposed by Elwyn Berlekamp in his 1970 work on polynomial factorization over finite fields. His original work lacked a formal correctness proof and was later refined and modified for arbitrary finite fields by Michael Rabin. In 1986 René Peralta proposed a similar algorithm for finding square roots in \mathbb F_p. In 2000 Peralta's method was generalized for cubic equations. Statement of problem Let p be an odd prime number. Consider the polynomial f(x) = a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adian–Rabin Theorem
In the mathematical subject of group theory, the Adyan–Rabin theorem is a result that states that most "reasonable" properties of finitely presentable groups are algorithmically undecidable. The theorem is due to Sergei Adyan (1955) and, independently, Michael O. Rabin (1958).Michael O. Rabin''Recursive unsolvability of group theoretic problems'' Annals of Mathematics (2), vol. 67, 1958, pp. 172–194 Markov property A ''Markov property'' ''P'' of finitely presentable groups is one for which: #''P'' is an abstract property, that is, ''P'' is preserved under group isomorphism. #There exists a finitely presentable group A_+ with property ''P''. #There exists a finitely presentable group A_- that cannot be embedded as a subgroup in any finitely presentable group with property ''P''. For example, being a finite group is a Markov property: We can take A_+ to be the trivial group and we can take A_- to be the infinite cyclic group \mathbb. Precise statement of the Adyan–Rabi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Powerset Construction
In the theory of computation and automata theory, the powerset construction or subset construction is a standard method for converting a nondeterministic finite automaton (NFA) into a deterministic finite automaton (DFA) which recognizes the same formal language. It is important in theory because it establishes that NFAs, despite their additional flexibility, are unable to recognize any language that cannot be recognized by some DFA. It is also important in practice for converting easier-to-construct NFAs into more efficiently executable DFAs. However, if the NFA has ''n'' states, the resulting DFA may have up to 2''n'' states, an exponentially larger number, which sometimes makes the construction impractical for large NFAs. The construction, sometimes called the Rabin–Scott powerset construction (or subset construction) to distinguish it from similar constructions for other types of automata, was first published by Michael O. Rabin and Dana Scott in 1959. Intuition To simulate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
