Availability:Arithmetic function (see is/2)
powm(+IntExprBase,
+IntExprExp, +IntExprMod)Result = (IntExprBase**IntExprExp)
modulo IntExprMod. Only available when compiled with
unbounded integer support. This formula is required for Diffie-Hellman
key-exchange, a technique where two parties can establish a secret key
over a public network.
IntExprBase and IntExprExp must be non-negative (>=0),
IntExprMod must be positive (>0).132The
underlying GMP mpz_powm() function allows negative values under
some conditions. As the conditions are expensive to pre-compute, error
handling from GMP is non-trivial and negative values are not needed for
Diffie-Hellman key-exchange we do not support these.
