The Crypto Wars
A technological backdoor is a secret portal giving someone access to a secure product, be it a smartphone app, a computer program, or a Web connection. Pure software backdoors let the government directly access systems like Gmail, Facebook, or WhatsApp, and read unencrypted communications. A more complex form of backdoor access involves the government using special keys to decipher encrypted data that it gathered through conventional interception.
Backdoors that rely on encryption keys can either involve a master key for all data flowing across a particular product or keys for individual users that can be plugged into a law-enforcement system to wiretap those people. When a company sets up its system to generate keys for law enforcement—whether for its entire product or for individual users—it holds onto those keys until it is compelled to produce them. This is called key escrow. Here, there is no portal for direct access. Instead, the software code that is written to create the encryption is designed to be able to spit out keys for the government.