Karatsuba Algorithm Explanation and Method

In 1962, the Karatsuba Algorithm (KA) was presented for multiplying two polynomials. Compared to the textbook or normal multiplication technique, it saves coefficient increases at the expense of additional alternatives. The basic KA is done in the following order. Consider A(x) and B(x), two degree-1 polynomials with n = 2 coefficients.


Multiplication is a massive arithmetic operation for various sign-handling applications, such as correlation, convolution, frequency analysis, and image processing. For the handling season of these applications, the speed of the duplicating activity is critical. In digital filtering, multiplication is an arithmetic application often used at the equipment level. Similarly, the efficiency of a multiplication activity serves as a foundation for the operation of modulators, cryptosystems, ALUs (Arithmetic Logic Units), and various other devices. O(n2) bit activities are required for integers of n-bits. In terms of the number of digit tasks, the complexity of the expansion activity is optimal. Regardless, the complexity of the growing movement isn’t great for large groups.

Many calculations have been investigated to upgrade the O(n2) multiplication bound. The Karatsuba duplication calculation is the easiest to perform. The Karatsuba calculation uses the gap and overcome process and takes O(nlog 3) cycle activities to multiply two numbers of n-bits. Karatsuba calculation conducts increased duties by replacing a few augmentations with less expensive deduction and expansion actions. Because of the recursion overhead, Karatsuba calculation is slower than the old-style augmentation technique for small contributions, but it is more efficient for large numbers. This review assumes that multiplication is achieved by a multiplicand and multiplier of equal length.


The simplest method for multiplication two n-digit whole integers is to use an old-style technique, often known as long multiplication, which involves O(n2) multiplication tasks. Numerous calculations are required to complete this requirement. The Karatsuba computation, which uses the gap and overcomes technique, is the most straightforward. For a 2-digit multiplication activity, the typical approach requires four increases. A 2-digit increase activity can be accomplished in the Karatsuba computation with three multiplication. Intel and other firms use the Karatsuba computation to conduct faster growth because it requires fewer improvements. The Karatsuba computation can also be done recursively and iteratively.

Karatsuba computation can be conducted recursively for considerable digit growth activity by separating multiplicand and multiplier. The cost of multiplication exceeds the cost of expansion and subtraction activities—for example, the computation of 97*98 multiplication activity using the Karatsuba calculation. Despite specific expansion and shift duties, the usual duplication technique determines this multiplication activity with four 1-digit increases. The Karatsuba computation, as shown in the flowchart, necessitates three multiplications and divisions and shift jobs to complete this increased activity. The outcome of the 16*17 action in sync C can be determined recursively using the technique by and by.

The Karatsuba calculation is investigated for multiplicands and multipliers with 4-, 8-, 16-, and 32-bits lengths. Furthermore, the Karatsuba computation is deconstructed regarding the amount of duplication and the total interaction time. The apps used for execution testing are written in MATLAB R2014a. The PC used for testing has the following features: Windows 7 64-bit operating system, Intel Core i5-3317U processor running at 1.70 GHz, and 4 GB RAM. A presentation assessment of the Karatsuba shows computation in terms of duplication quantity for various component lengths. Because the Karatsuba computation is handled, the bit length increases in tandem with the amount of increase.

In addition, as the number of multiplication increases, so does the quantity of hardware. As a result, the cost of completing duplication actions grows. The amount of multiplication of Karatsuba computation is not precisely an old-style increase technique compared to one another. The Karatsuba computation is analysed for the absolute interaction time for various component lengths. The total cycle duration increases as the digit length increases, as shown in the diagram. This is because the number of required multiplications grows in proportion to the length.

Furthermore, the total interaction duration is proportional to the handling speed. The handling velocity of multiplication decreases as the total interaction time increases. Compared to the traditional augmentation technique, the Karatsuba calculation produces better results in terms of cycle time.

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