Subject: System Web Security

Topic: Software Security

Difficulty: High

• DRM technologies attempt to give control to the seller of digital content or devices after it has been delivered.
• DRM technology prevents the consumer from unauthorized access, restricts the user from copying the contents and converting it to other format.

• Following are some examples of digital right management.

  i. A company set it’s servers to block the forwarding of sensitive e-mails.

  ii. An e-book server restricts access to, copying of and printing of material based on contraints set by the copyright holder of the content.

  iii. A movie studio includes software on its DVDs that limit the number of copies a user can make to two.

• DRM technology enables content publishers to enforce their own access policies on contents, such as restriction on copying or viewing.

• Common DRM techniques

  The techniques for DRM include:

  i. Restrictive licensing agreement This technique controls access to digital contents, copyright and public domain. It also imposes some license agreements before downloading software.

  ii. Encryption, scrambling of expressive material and embedding of a tag This technique controls access and reproduction of online data. It also includes backup copies for personal use.

• DRM framework

  1. The idea DRM system is flexible and entirely transparent to the user.

  2. All digital right management scheme operates on three levels:

     a. Establishing a copyright.

     b. Managing the distribution of copyrighted content.

     c. Controlling what a customer can do with content.

  3. To accomplish this level of a control a DRM program has to define three entities:

     a. User

     b. Content

     c. User rights.

  4. It also specifies a relationship among them.

  5. Let’s consider an example of simple DRM scheme for mp3-download site.

  6. Aditi wants to download lauryn Hill’s :”Everything is everything”. So she logs on to a site to which she subscribes.

  7. The subscription allows her five downloads per month.

  8. Here, the user is aditi and content is the song “Everything is Everything”.

  9. And the usage rights are specified as follows:

     a. Can she download it, or has she already downloaded 5 files in a month?

     b. Can she copy it or is she downloading an encrypted file?

  10. Usage right also include obligations related to transaction

  11. For example, does she need to pay extra for this download?

  12. This would be the relationship between aditi, the song and the rights.

  13. Figure1 explains the above example

Technologies:

• DRM and computer games.

  1.1 Limited install activations.

  a. Computer games sometimes use DRM technologies to limit the number of systems the game can be installed on by requiring authentication with an online server.

  b. Most games with this restriction allow three or five installs, although some allow an installation to be 'recovered' when the game is uninstalled.

  1.2 Product Keys

  a. One of the oldest and least complicated DRM protection methods for the computer games is a product key, a typically alphanumerical serial number used to represent a license to a particular piece of software.

  b. During the installation process for the software, the user is asked to input the key; if the key correctly corresponds to a valid license (typically via internal algorithms), the key is accepted, and installation can continue.

• DRM and documents

  i. Enterprise digital rights management (E-DRM or ERM) is the application of DRM technology to the control of access to corporate documents such as Microsoft Word, PDF, and AutoCAD files, emails, and intranet web pages rather than to the control of consumer media.

  ii. E-DRM, now more commonly referenced as IRM (Information Rights Management), is generally intended to prevent the unauthorized use (such as industrial or corporate espionage or inadvertent release) of proprietary documents. IRM typically integrates with content management system software but corporations such as Samsung Electronics also develop their own custom DRM systems.

• DRM and e-books

  i. Electronic books read on a personal computer, or an e-book reader or e-reader app typically use DRM technology to limit copying, printing, and sharing of e-books. E-books (alternatively spelled "ebooks") are usually limited to be used on a limited number of reading devices, and some e-publishers prevent any copying or printing

• DRM and film

  i. An early example of a DRM system is the Content Scrambling System (CSS) employed by the DVD Forum on film DVDs circa 1996. CSS uses an encryption algorithm to encrypt content on the DVD disc.

  ii. Manufacturers of DVD players must license this technology and implement it in their devices so that they can decrypt the encrypted content to play it. The CSS license agreement includes restrictions on how the DVD content is played, including what outputs are permitted and how such permitted outputs are made available. This keeps the encryption intact as the video material is played out to a TV.