Bignum representations
% Remco Bloemen % 2009-11-28, last updated 2014-03-03
Montgomery Residue Number System (Monty BuRNS)
\mathcal{M} = \left\{ m_i \vert m_i \mathrm{\;is\; prime},\; i \in [0,N-1] \right\}
\displaystyle M = \prod_{\mathcal{M}}\^{m} m
x_i = X\cdot2\^{64} \mod m_i
z_i = x_i + y_i \mod m_i
z_i = x_i \cdot y_i \mod m_i
z_i = x_i y_i\^{-1} \mod m_i
Positional notation
X_n = \left\lfloor x b\^{-n} \right\rfloor \mod b
x = \sum_{[0,N]}\^{n} X_n b\^n
Advantages
GMP!
Disadvantages
Not easily distributable.
Chinese remainder theorem
Advantages
Easy to make distributable.
Disadvantages
No GMP!