IBM researchers are collaborating with Signal and Threema to redesign encrypted messaging protocols to address future quantum computing threats. Cryptologist Ethan Heilman pointed out that compared to Bitcoin, instant messaging applications face a more direct risk of "store-and-forward" attacks, as the communication content of Bitcoin may be recorded immediately and decrypted later. Signal has already deployed post-quantum upgrade solutions such as PQXDH and SPQR, while Threema is exploring the integration of NIST standardized ML-KEM algorithms. The report highlights the challenges of making these quantum-resistant protocols operate efficiently without significantly increasing bandwidth.