Digital-Ticket-Controlled Digital-Ticket Circulation
By Ko Fujimura,
Hiroshi Kuno, Masayuki Terada, Kazuo Matsuyama, Yasunao Mizuno and Jun Sekine
Summarized by Dominique Kilman (dkilman@uiuc.edu)
Overview:
This paper presents a digital ticket scheme that is designed to work as both a digital certificate and digital cash. Tickets can be issued, transferred and redeemed. The control tickets are the Redeem and Transfer tickets that are created by the owner of a ticket when either of these processes is initiated. Tickets are divided up into Ticket-Types (header with generic type information) and Ticket (specific for each individual ticket).
Ø Suggests using “Control Tickets” to control ticket circulation. These control tickets can be recursively defined so a control ticket is controlled by a higher level control ticket, etc
Ø The same ticket system is designed to be used for certificates and digital cash
Ø None of the details of signing or authentication are provided
Ø The transfer process raised some discussion as to whether a list scheme will really be secure. The scheme defined in the paper seems to work because the original ticket is never changed
Ø Ticket-types are used to define the way in which a ticket can be used and any constraints on the ticket. There will be a predefined number of types that are publicly available.
Ø They
have very little in the Protocol section of the paper. And one of the problems raised was that the
receiver must trust the sender of a ticket to always truthfully state the
ticket type
Partial Conclusions
Ø Does not seem to be a very innovative idea, just a combination of existing ideas about certificates and digital cash.
Ø It
seems to rely on some kind of Public Key signing process, but what this process
is was never discussed.