Encryption is process of turning a plaintext to jargon or the method of changing confidential file to jargon in order prevent unauthorized persons to gain access to confidential message. Message is the transfer of information from the sender to the receiver through a particular medium. Encryption is the most effective process for achieving data security. The process of Encryption hides the contents of a message in a way that the original information is recovered only through a decryption process. This paper presents an Encryption/Decryption application of messages on both java and Android phones. The method of encryption of message in this paper is AES (Advance Encryption System) where the same key that is used to encrypt is used to decrypt. The Encryption key is entered into the mobile phone text field by the user. The same encryption key is also used to decrypt the encrypted binary file.
Keywords: Encryption, Decryption, plain text, mobile phone, cipher key