Description:
<jats:title>Abstract</jats:title>
<jats:p>Loss of secret keys is the deadly attack in public key cryptosystems. We present an identity-based threhold key-insulated proxy signature (IBTKIPS) scheme to settle the problem of key exposure in the identity-based proxy signature system. The proposed IBTKIPS scheme is secure in the standard model. In the IBTKIPS scheme, we use at least <jats:italic>k</jats:italic> out of <jats:italic>n</jats:italic> helper keys to refresh the temporary secret keys. The IBTKIPS scheme is more flexible and securer than the identity-based proxy signature scheme.</jats:p>