Boneh and Venkatesan have recently proposed a polynomial time
algorithm for recovering a ``hidden'' element \alpha of a
finite field \F_p of p elements from rather short
strings of the most significant bits of the remainder
mo\-du\-lo p of \alpha t for several values of t selected uniformly
at random ... more >>>

Boneh and Venkatesan have recently proposed a polynomial time
algorithm for recovering a ``hidden'' element \alpha of a
finite field \F_p of p elements from rather short
strings of the most significant bits of the remainder
mo\-du\-lo p of \alpha t for several values of t selected
uniformly at ... more >>>

We show that for several natural classes of ``structured'' matrices, including symmetric, circulant, Hankel and Toeplitz matrices, approximating the permanent modulo a prime p is as hard as computing the exact value. Results of this kind are well known for the class of arbitrary matrices; however the techniques used do ... more >>>