Novel Formulations of M-Term Overlap-Free Karatsuba Binary Polynomial Multipliers and Their Hardware Implementations
Madhan Thirumoorthi, Alexander J. Leigh, Moslem Heidarpur, Mohammed Khalid, Mitra Mirhassani
Abstract
Novel binary polynomial multipliers have been designed using M-term overlap-free Karatsuba multiplication (OFKM), where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$M$ </tex-math></inline-formula> is 5–8. The proposed designs were realized in digital hardware and implemented on field-programmable gate array (FPGA) and the best value of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$M$ </tex-math></inline-formula> was selected and presented for common National Institute of Standards and Technology (NIST) operand sizes from 64 to 571 bits. The implemented hardware designs use a hybrid approach that combines a given M-term overlap-free Karatsuba multipliers with two-term splitting to reduce the need for zero-padding in the final recurrent stages. Compared to the traditional M-term Karatsuba multipliers, the proposed overlap-free implementations offer reductions in delay and area-delay product (ADP). The proposed designs also compare favorably to previous implementations of binary polynomial multipliers. Their favorable characteristics make the proposed overlap-free Karatsuba polynomial multipliers viable options for use in cryptographic systems where speed is a significant consideration and hardware resource consumption must be limited.