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Any pseudorandom bit generator can be used to construct a block private key cryptos system which is secure against chosen plaintext attack, which is one of the strongest known attacks against a cryptosystem.Expand

A formalization of chosen ciphertext attack is given in the model which is stronger than the "lunchtime attack" considered by Naor and Yung, and it is proved a non-interactive public-key cryptosystem based on non-Interactive zero-knowledge proof of knowledge to be secure against it.Expand

A computational complexity theory of the “knowledge” contained in a proof is developed and examples of zero-knowledge proof systems are given for the languages of quadratic residuosity and 'quadratic nonresiduosity.Expand

These procedures nearly achieve recently established lower bounds on the amount of space inherently required to solve the covering and boundedness problems for vector addition systems, and so are much more efficient than previously known non-primitive-recursive decision procedures.Expand

Results are derived suggesting that the undirected reachability problem is structurally different from, and easier than, the directed version of NSPACE(logn), an affirmative answer to a question of S. Cook.Expand

It is shown that a given sentence does not change in truth value when each of the quantifiers is limited to range over an appropriately chosen finite set of rationals and this fact leads to a new decision procedure for S which uses at most space.Expand

It is shown that any multivariate polynomial of degree d that can be compute sequentially in C steps can be computed in parallel in O(1) using only $(Cd)^{O(1)} processors.Expand

It is proved that for every N there is a JAG which can determine threadability of an arbitrary N node input graph in storage $O((log N)^2 )$, where the storage of a J AG with Ppebbles and N states is defined to be $P\log N + \log Q$.Expand