Messaging apps have one year to move the data of their Iranian customers onto servers in Iran, Reuters reported on Sunday. The decision, from a country that already has some of the strictest controls on Internet communications, will affect foreign companies that operate messaging services in the country.

Known for their hacking prowess, Iran's government agencies would likely have easier access to penetrate secure messaging platforms once the decision is implemented.

"Foreign messaging companies active in the country are required to transfer all data and activity linked to Iranian citizens into the country in order to ensure their continued activity," Iran's Supreme Council of Cyberspace said, according to Reuters.

Complying with the decision won't be practical for many app makers, some of whom rely on third-party servers to transmit messages. It also won't be easy for larger companies like Apple, whose recent spat with the FBI demonstrated its commitment to strong encryption for its iMessage service.

The decision also comes as the popularity of secure messaging apps has risen sharply in Iran. More than 20 million Iranians use the Telegram messaging service out of a total population of 80 million, according to Reuters. Telegram has won over security-conscious users in part because it has a "secret" mode that stores the encryption key on the users' devices, rather than on an internet server.

Iranians have proven adept at using technology to circumvent strict government rules in the past. The Gershad app, launched in February, helps Iranian women track the morality police in large cities, so they can avoid being stopped for minor dress code violations.