The invention provides a method, system, and computer program product to
control the access, copying, and/or transfer of a digital asset by
mobile, wireless devices using a digital voucher. The digital voucher
references a primary content that contains all of the expression for that
particular asset and a secondary content that contains information that
can be distilled out as a preview. The information in the primary content
can be limited to a specified duration or a specific number of viewings.
The author, owner, or possessor of the digital asset specifies the terms
and conditions for distribution of the digital asset. The digital voucher
authorizes the mobile, wireless device to access a specified primary or
secondary content that may be located elsewhere in the network. The
mobile, wireless device can download a copy of portions or all of the
content depending on the terms specified in the voucher.