In an e-learning system, while the documents are transmitting between the communicating parties, authentication is too much necessary. Digital watermarking along with the encryption technique may be used to provide authenticity. International Data Encryption Algorithm (IDEA) is one of the very useful symmetric key cryptographic algorithms, which is also free to all for any users, can be used for the key selection for encryption and 3DES can be used for watermark key selection. Digital watermarking is one of the very popular authentication techniques. So, while transmittingany document like registration certificate in any e-learning system, which should be transmitted from the developer to learner, the developer can use this technique to make a secure transaction. As we know that certificate is very essential document for any kind of learning, if the hacker can reach the document while transmitting from developer to learner, he can modify or destroy the documents. If the  developer uses our proposed technique while transmitting, and if the hacker makes any changes, then it affects the watermark, and easily identified. In this situation, student can also ask for retransmitting the certificate