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).

 

Discussion Points

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.