We give a new construction of pseudorandom generators from any one-way
function. The construction achieves better parameters and is simpler than that
given in the seminal work of Hastad, Impagliazzo, Levin and Luby [SICOMP '99].
The key to our construction is a new notion of next-block pseudoentropy, which is
inspired by the notion of "inaccessible entropy" recently introduced in [Haitner
et al., STOC '09]. An additional advantage over previous constructions is that
our pseudorandom generators are parallelizable and invoke the one-way function in
a non-adaptive manner. Using [Applebaum, Ishai, Kushilevitz, SICOMP '06], this
implies the existence of pseudorandom generators in NC^{0} based on the
existence of one-way functions in NC^{1}.