Method for adding and multipying redundant binary and apparatus for adding and multipying redundant binary

A method for adding a redundant binary, the method for multiplying the redundant binary, a redundant binary adder, and a redundant binary multiplier are provided to offer an adder functioning as a combiner in an encryption system for securing data without carry transfer, and reduce spatial and time complexity. A first addition block(151) generates a first addition result comprising a carry, which is a binary value, and a sum, which is a negative number, by performing first addition adding a redundant binary for 'X' and the binary value of 'Y'. A second addition block(152) generates second first addition result comprising the carry, which is the negative number, and the sum, which is the binary value, by performing second addition adding the carry of a previous digit among the carries of the first addition, the sum of the first addition, and the negative number for 'Z'. 'i' bit of the redundant binary for 'X' comprises a symbol bit 'xi^s' and a bit value 'xi^v'.