Encryption has become a part and parcel of our lives and we have accepted the fact that data is going to encrypted and decrypted at various stages. However, there is not a single encryption algorithm followed everywhere. There are a number of algorithms existing, and I feel there is a need to understand how they work. So this text explains a number of popular encryption algorithms and makes you look at them as mathematical formulas.-Encryption has become a part and parcel of our lives and we have accepted the fact that data is going to encrypted and decrypted at various stages. However, there is not a single encryption algorithm followed everywhere. There are a number of algorithms existing, and I feel there is a need to understand how they work.　 So this text explains a number of popular encryption algorithms and makes you look at them as mathematical formulas.