Without the assumption that the private keys are kept secure perfectly, cryptographic primitives cannot be deployed in the insecure environments where the key leakage is inevitable. In order to reduce the damage caused by the key exposure in the identity-based(ID-based) signature scenarios efficiently, we propose an ID-based key-insulated signature scheme in this paper, which eliminates the expensive bilinear pairing operations. Compared with the previous work, our scheme minimizes the computation cost without any extra cost. Under the discrete logarithm(DL) assumption, a security proof of our scheme in the random oracle model has also been given. Without the assumption that the private keys are kept secure perfectly, cryptographic primitives can not be deployed in the insecure environments where the key leakage is inevitable. Under the discrete logarithm (DL) scenario efficiently, we propose an ID-based key-insulated signature scheme in this paper, which eliminates the expensive bilinear pairing operations. assumption, a security proof of our scheme in the random oracle model has also been given.