Branching programs are a well-established computation model
for Boolean functions, especially read-once branching programs
have been studied intensively. Exponential lower bounds for
deterministic and nondeterministic read-once branching programs
are known for a long time. On the other hand, the problem of
proving superpolynomial lower bounds ... more >>>

We present several new and fairly practical public-key encryption
schemes and prove them secure against
adaptive chosen ciphertext attack. One scheme is based on Paillier's
Decision Composite Residuosity (DCR) assumption,
while another is based in the classical Quadratic Residuosity (QR)
assumption. The analysis is in the standard ... more >>>

One of the most basic pattern recognition problems is whether a
certain local feature occurs in some linear array to the left of
some other local feature. We construct in this article circuits that
solve this problem with an asymptotically optimal number of
threshold gates. Furthermore it is shown that ... more >>>