Data security refers to protect digital privacy measures that are applied to prevent unauthorized access to computers, databases and websites. Confidentiality is one of the most important part of security and the principle of confidentiality ensures only the sender and the intended recipients have access to the contents of a message. There are a number of algorithms using encryption and decryption procedure to achieve security measures for data and information. Each algorithm has different method. For encrypting and decrypting large number of data sets, most of the algorithms are complex and some existing algorithms are vulnerable to cryptanalysis attacks. The main objective of our research work is to build a simple algorithm which can encrypt and decrypt large number of data sets and is free from maximum cryptanalysis attack to provide confidentiality. In this research paper, an effective symmetric cryptographic algorithm is proposed where the algorithm procedures are much simpler to encrypt or decrypt large number of data sets. Security level is higher because poly-alphabetic substitution mapping method, translation and transposition techniques are used.