The French embassy in Washington has transmitted the first diplomatic letter encrypted to withstand future quantum computers, according to President Emmanuel Macron. France's first "post-quantum" encrypted message included comments about collaboration with the U.S. 

The transmission was part of President Emmanuel Macron's Quantum Plan, unveiled in January 2021. The action is in line with the G7 forum's call for cooperation on key matters relating to the growth of the quantum industry and the development of post-quantum cryptography solutions during its Munich meeting in 2022. 

According to a statement from the Paris foreign ministry, the embassy sent the encrypted message using software developed by startup CryptoNext. CryptoNext is creating post-quantum cryptography solutions as a result of research by the French National Institute for Research in Digital Science and Technology, the French National Centre for Scientific Research and Sorbonne University.

Digital security experts assert that quantum computers will inevitably break current cryptographic methods. France is seeking to create and master encryption technologies that will safeguard the country's private communications in the future.

"Tomorrow, a sufficiently powerful quantum computer will be able to break all cryptographic algorithms and decode our messages," Macron wrote on Twitter.

Related:US and France Establish Bilateral Partnership to Advance Quantum Goals

"To counter this threat, developing post-quantum encryption technologies is a strategic concern. And that's what we're doing!"

The ministry noted that as part of a larger €1.8 billion drive to develop various quantum technologies, France allocated €150 million ($157 million) to quantum-resistant cryptography.

The announcement said that the measure "is a forerunner to changes in France's essential digital infrastructure" and that a government "action plan" for "migration to post-quantum cryptography" would be released in the first quarter of 2023.

In May, the White House unveiled its strategy to help businesses and spy agencies transition to post-quantum cryptography.