IBM is collaborating with Signal and Threema to design an encrypted messaging system that can withstand quantum attacks.

PANews reported on March 11 that, according to Decrypt, IBM researchers are collaborating with Signal and Threema to design a messaging system resistant to quantum attacks. Cryptography researcher Ethan Heilman points out that due to the possibility of "store-first, decrypt-later" attacks, encrypted messaging platforms may face greater near-term quantum risks than Bitcoin—attackers now intercept and store encrypted data, waiting to crack it once quantum computers become more advanced.

Signal introduced the PQXDH upgrade in 2023 to protect new sessions, and in 2025, it extended post-quantum protection to continuous messaging, calls, and media through the SPQR protocol upgrade. Threema is collaborating with IBM to explore integrating the NIST-standardized ML-KEM algorithm into its systems. The research also focuses on protecting metadata, but simply replacing existing components could lead to a significant increase in bandwidth, necessitating a complete redesign of the protocol from the ground up.