We don't need to look to fiction in the US to see examples of encryption controlled by the State with laws, it was literally US government policy in the 90s/early 2000s. Examples include banning export of encryption keys longer than 40 bits etc to make it easier for US secret services to crack the foreign purchaser's systems, the debate during the Clinton administration on what should be permitted encryption-wise was intense at times.

> https://en.wikipedia.org/wiki/Crypto_Wars

> https://en.wikipedia.org/wiki/Export_of_cryptography_from_th...