Abstract: An advertising control method is described. The method includes receiving an advertisement identification message (AIM) at a first mobile device, sending the AIM from the first mobile device to a content display unit (CDU) and storing the AIM in the CDU, selecting at least one content item from among a plurality of content items based, at least in part, on at least one stored AIM, the stoned AIM being stored in the CDU, and displaying the selected content item on the CDU. Related apparatus and methods are also described.

Abstract: A system and a method for providing variable security mechanisms for securing digital content, in which a single security mechanism is not used for all content. Instead, at least one characteristic or feature of the security mechanism is varied between units, instances or categories of content Therefore, even if unauthorized access is gained to a single unit of content, the overall integrity and security of the system for content distribution is not compromised. Preferably, security is provided through a general mechanism, which is then varied in order to provide variable, dissimilar security schemes for different types of content. By “type of content”, it is meant any of a single unit of content, a single instance of content or a single category of content. For example, for a category of content, the content may be characterized according to the identity of the content itself, such as the title of a movie for example, and/or according to the owner of a particular copy of the content.