A signed multiplication method and a corresponding device for multiplying a first multiplicand with a second multiplicand. The device stores the first multiplicand in a first register as a first vector of at least one respective digit and storing the second multiplicand in a second register as a second vector of at least one respective digit, each digit having a pre-determined number of bits. The method further converts the digits of the first vector and the second vector to corresponding digits of one bit less each than the pre-determined number of bits. A processor effects signed multiplication of the multiplicands.