history-of-drm

Updated: June 2, 2021

Author: Tim Siglin

link: https://www.streamingmedia.com/Articles/ReadArticle.aspx?ArticleID=144341 tags :: R:tech, R:video

• Dvd Jon

• Biggest limitation to scaling DRM is the computational intensity of certain steps in encryption, and the license generation process

Symmetric vs Assymmetric keys

• Current line of thinking

  • Use Symmetrical keys for encryption and decryption of media (AES based)
  • Use assymmetrical cryptography for license key generation

• What is AES? “AES is a symmetric cryptographic algorithm that takes its name from the key length, such [as] AES-128, AES-192 and AES-256.”

  • http://go2sm.com/sciencedirect1

• Symmetric key for licensing used to be the norm during the VHS to DVD era, but this could be hacked. The shift from symmetric to assymetric cryptography for license generation is a key step in the evolution of DRM tech

• RSA for private key was not as robust as it was considered

  • The Irony (and Dangers) of Predictable Randomness - https://blog.keyfactor.com/the-irony-and-dangers-of-predictable-randomness

ECC / Elliptical Curves

• Unlike the RSA approach, which uses basic multiplication of two primes to generate factors on which to decode the key, ECC uses points on a curve. ECC keys are ephemeral, meaning that they’re ideal for sessions-based use cases, such as a streaming DRM license.
  • ECDHE - Elliptical Curve Diffie Hellman Exchange
  • Use modulo prime instead of regular prime numbers
  • ECCDSA - Digital Signature Algorithm - to guarantee that the contents of the critical messages sent from the server to desktop or web application will not be altered in transit