Exponentiation By Squaring
Exponentiating by squaring is a general method for fast computation of large integer powers of a number. Some variants are commonly referred to as square-and-multiply algorithms or binary exponentiation. In additive notation the appropriate term is double-and-add. These can be of quite general use: for example in modular arithmetic or powering of matrices.
Read more about Exponentiation By Squaring: Underlying Idea, 2k-ary Method, Sliding Window Method, Montgomery's Ladder Technique, Fixed Base Exponent, Yao's Method, Euclidean Method, Further Applications, Signed-digit Recoding, Alternatives and Generalizations