The present invention discloses a method and a server for authentication adaptive to a secured application. The method comprising encrypting a part of continuous streams of random real-time data using a user's public key to form a first encrypted data when the request is received from a first entity, transmitting the first encrypted data to the first entity, wherein the first entity communicates the first encrypted data to a second entity, receiving a second encrypted data from the second entity, wherein the second encrypted data is created by decrypting the first encrypted data using a user's private key and encrypting the decrypted data using the user's private key, authenticating the second encrypted data received from the second entity by comparing data decrypted from the second encrypted data with the part of continuous streams of random real-time data stored in the authentication server and initiating action based on authentication.