A digital ticket is procured by a client ticket consumer upon, preferably,
the Internet from and by staged interaction with a ticket provider
server. The digital ticket becomes embodied in a tangible transportable
data storage medium, normally a 2-D bar code printed on paper by the
consumer, or on the consumer's flexible disk or smart card, containing
Sign(s,I||hash(R))||R where (1) R is a number having its origin in the
computer of the ticket consumer, which number R is appended to (2) a
number Sign(s,I||hash(R)). This number Sign(s,I||hash(R)) was earlier
computed in the computer of the ticket provider as a digital signature
using signature key s of a number hash(R) combined with event information
I, and was subsequently communicated across the communications network to
the computer of the ticket consumer. The number hash(R) was itself even
earlier computed in the computer of the ticket consumer as a one-way
function of random number R, which computed one-way function was
subsequently communicated to the computer of the ticket provider. The
number R is private to the ticket consumer and not public; the digital
signature key s is private to the ticket provider.The digital ticket is
redeemed by (1) transporting the transportable storage medium within
which the Sign(s,I||hash(R))||R is written to the particular selected
event; (2) tendering the digital ticket for verification and for
admission; (3) reading the Sign(s,I||hash(R))||R to an event computer and
extracting the number R; (4) decrypting the remaining Sign(s, I||hash(R))
with verification key v of the ticket producer to get hash(R) and I; (5)
re-calculating from R, with the same one-way function previously used, a
re-calculated hash(R); then, having this recalculated hash(R) to hand;
(6) comparing the re-calculated hash(R) to the extracted hash(R). The (4)
decrypting will work, producing a proper I for the selected event, and
the (6) comparing will be equal, only for a legitimate ticket.