Many Internet applications require intensive cryptographic calculation such as public-key encryptions and digital signatures. These schemes require a computation of large integer multiplications. Those cryptographic schemes are vulnerable to a brute-force attack, and the large key is the countermeasure. In practice, the key size that makes brute-force attack impractical will slows down the speed of encryption and decryption. Multiplication of two very long integers usually takes time to compute. Distributed Karatsuba algorithm is proposed to reduce the time of multiplication of two very long digits. The proposed architecture that makes use of Karatsuba algorithm achieves faster multiplication.