Internet play a vital role for sharing information
online but this mode is dangerous for data hacking and
cracking by the unauthorized person. Information security
is an important requirement of today world due to
increasing use of internet. The privacy of information can
be achieved through cryptography by applying the
encryption process on the plain text being transmitted over
network. Encryption is the process of converting the
original text into cipher text so that only intended receiver
of the message can read it.
In this paper we proposed a new ASCII code based
substitution technique for text encryption which is more
secure than Caesar Cipher substitution technique and
proposed technique is implemented in java. In the proposed
technique we used the ASCII value of the character and the
position of the alphabet for encrypting the plain text.
Keywords : Cryptography, Substitution, Encryption, Decryption, ASCII Value.