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Apple is future-proofing iMessage with post-quantum cryptography

On Feb. 21, Apple introduced PQ3, which they claim is “the most significant cryptographic security upgrade in iMessage history,” for iOS 17.4.

With the introduction of the new protocol, Apple is now one of only a few providers that offer post-quantum cryptography for messages. While Signal launched a “quantum resistant” encryption upgrade back in Sep. 2023, Apple claims to be the first to achieve “level 3” encryption.

Image source: Apple Security blog

According to Apple:

“PQ3 is the first messaging protocol to reach what we call Level 3 security — providing protocol protections that surpass those in all other widely deployed messaging apps. To our knowledge, PQ3 has the strongest security properties of any at-scale messaging protocol in the world.”

Post quantum messaging

Apple’s iMessage has featured end-to-end encryption since its inception. Initially using RSA encryption, the company switched to Elliptic Curve cryptography (ECC) in 2019. While current encryption methods are considered secure due to the amount of time and computing power required to break them, the threat of quantum computing is looming.

Theoretically, a quantum computer could break today’s encryption methods with relative ease. Though there are no current quantum computing systems capable of doing so, the rapid pace of advancement has led organizations around the world to begin preparations to develop post-quantum cryptography methods to safeguard data against potential future attacks.

Quantum safe encryption

There is currently no specific timeframe for the emergence of quantum computers capable of breaking standard cryptography. IBM claims an inflection point in quantum computing by 2029, while MIT/Harvard spinout QuEra says they will have a 10,000-qubit error-corrected system by 2026.

However, there are concerns that bad actors could be harvesting encrypted data illicitly and storing it for decryption later, known as a HNDL attack (harvest now, decrypt later), even before they have access to quantum computers.

Related: Oxford economist who predicted crypto going mainstream says ‘quantum economics’ is next