Analysis on Token-Controlled Public Key Encryption

In this paper, we analyze on the use of token-controlled public key encryption (TCE)schemes. We argue that for many of the applications in some possibilities of application in financial or legal scenarios, for example, the millionaire´s will problem, the `private-opening´ commitment, the scheduled payment problem, and the sealed-bid auctions and electronic lotteries problem, in the literature, the use of token-controlled public key encryption on its own, leads to inadequate solutions. We suggest that when considering applications of TCE, it is advisable to pay close attention to the lack of authentication and incorporate defences against the problems highlighted in this paper.