Pairing-based cryptosystems have been one of the most active areas in elliptic curve cryptography since 2000. The pairings can be evaluated in polynomial time by Miller’s algorithm. Many useful techniques have been suggested for optimizing the computation of the pairings. One of the most elegant techniques for computing the pairings efficiently is to shorten the iteration loop in Miller’s algorithm. Pairing based schemes have been designed for various applications that have certain advantages over conventional RSA or discrete logarithm based encryption schemes. The concept of pairing was first introduced by Andre Weil in 1940. It plays an important role in the theoretical study of the arithmetic of elliptic curves and Abelian varieties. A lot of pairing based schemes exist in literature but all cannot be implemented in practice due to security reasons. In the present paper we shall study different types of attacks on pairing based schemes.