A method for financing multimedia content through advertising includes
playing back advertising blocks between uses of the content so to finance
use of the content by the advertising. Code elements of a key are
embedded in predefined locations in the advertising blocks, the key being
configured for decryption of the content that follows. The embedded code
elements are scanned and collected during the playback of the advertising
blocks. The code elements are linked schematically to form the key. The
content is encrypted using the key so that a use of the content depends
on at least one of a subset of the code elements determined by the
advertiser and the key.