Patent ID: 11755288

Abstract:
An electronic calculating device (100) arranged to convert an input number (y) represented ((y1, y2, . . . , yk)) m a residue number system (RNS) to an output number represented in a radix representation ((e0, e1, . . . es−1)), the calculating device comprising an input interface (110) arranged to receive the input number (y) represented in the residue number system, and a processor circuit (120) configured to iteratively update an intermediate number (ŷ) represented in the residue number system, wherein iterations produce the digits (e0, e1, . . . es−1) in the radix representation with respect to the bases (b0, b1, . . . , bs−1), at least one iteration comprises computing the intermediate number modulo a base (bt) of the radix representation to obtain a digit (et=(ŷ)bt) of the radix representation, updating the intermediate number (ŷ←(ŷ−et+F)/bt) by subtracting the digit from the intermediate number, adding an obfuscating number (F; Ft), and dividing by the base (bt).