Representing a number of assets on an originating computer begins with
selecting the assets to be represented. Cryptographic hash asset
identifiers are generated; each of the asset identifiers is computed
using the contents of a particular asset. The asset identifier is a
content-based or content-addressable asset name for the asset and is
location independent. An asset list is generated that includes the asset
identifiers computed from the assets. A cryptographic hash asset list
identifier is generated that is computed from the asset list. The asset
list identifier is stored for later retrieval. The assets selected are
also stored for safekeeping either locally or on a computer network. In
the event of loss of the files from the originating computer, the asset
list identifier is retrieved. Using the asset list identifier, the
original asset list is found and retrieved from its safe location. The
asset identifiers from the retrieved asset list are used to find and
retrieve the individual assets from their backup locations. The assets
are verified by recomputing the cryptographic hash asset identifier for
each asset retrieved and comparing it to the asset identifier from the
asset list. The MD5 algorithm is used for the cryptographic hash
function. Assets are retrieved using a multicast protocol. A series of
importer programs searches for assets to retrieve in progressively more
remote locations. Assets are retrieved whole or in segments.