The efficiency of the cryptographic algorithm is generally not based on encryption and decryption time, but also depends upon the numbers of levels used to convert plain text to cipher text. RSA is one of the widely used algorithms of the public key cryptosystem. Since every algorithm has some certain limitations. And sometimes it may be not guaranteed that the cipher text can be fully secured. ASCII characters for representation of text are one of such limitations in the past cryptosystem. To overcome the above-mentioned limitation, an innovative algorithm namely modifies RSA was proposed with K-Nearest Neighbor, in which computational time for encryption and decryption was tabulated. This paper chapter presents the literature survey on the result of above-done experiment and tried to find how encryption and decryption time vary.