Android, FreeBSD, Linux, MacOS, OpenBSD, and Windows. Just about anyware.
C++11 is required. C++17 for Qt 6.
Qt LTS is supported. Qt 4.8.x is obsolete.
Data authentication is provided by SHA3-512 HMAC. Encryption is not necessary!
Key = (Local Address xor Peer Address) || (Local Port xor Peer Port) || (Caissa)
Digest = HMAC(Data, HMAC(Key, "QtChess" || 0x01))