TLDR: It's not Post-Quantum-Safe ("PQS")and it's very easy for anyone to collect more than 8GB of data per day to be later decrypted making all messages sent over matrix as decryptable in ~10 years.

https://github.com/matrix-org/matrix-spec/issues/975#issuecomment-2166193833

Matrix is in my humble opinion still the best available protocol, but until PQS is imlemented you should instead use SimpleX or Session (note that session's E2EE might not be PQS, but it's transmission layer is)

#Security #Privacy #Matrix #Quantum #QuantumAge #PostQuantumSafe #PQS