Schnorr Signature Scheme with Restricted Signing Capability and Its Application
Chul-Joon Choi, Zeen Kim, Kwangjo Kim · 2003
Key exposure can cause serious problem without knowing the loss of secret key. In the current signature scheme, if we are not aware of lost key, then, an impersonator can generate as many signatures as he/she wants. Furthermore this problem can cause great damages to us. Therefore, it is important to construct a signature scheme strong against key exposure problem. But it is an open problem to find a practical signature scheme with resistance to key loss problem.