This paper defines the AES password algorithm used as a symmetric-key-based password algorithm, and proposes the design of parallel password algorithm to utilize the resources of multi-core processor as much as possible. The proposed parallel password algorithm was confirmed for parallel execution of password computation by allocating the password algorithm according to the number of cores, and about 30% of performance increase compared to AES password algorithm. The encryption/decryption performance of the password algorithm was confirmed through binary comparative analysis tool, which confirmed that the binary results were the same for AES password algorithm and proposed parallel password algorithm, and the decrypted binary were also the same. The parallel password algorithm for multi-core environment proposed in this paper can be applied to authentication/payment of financial service in PC, laptop, server, and mobile environment, and can be utilized in the area that required high-speed encryption operation of large-sized data.