-All following encryption is done using
-@url{https://www.schneier.com/academic/twofish/, Twofish} algorithm with
-256-bit key in
-@url{https://en.wikipedia.org/wiki/Counter_mode#Counter_.28CTR.29, CTR}
-mode of operation with zero initialization vector (because each
-encrypted packet has ephemeral exchange key). @url{https://blake2.net/,
+All following encryption is done using @url{https://cr.yp.to/chacha.html,
+ChaCha20} algorithm. Data is splitted on 128 KiB blocks. Each block is
+encrypted with increasing nonce counter. @url{https://blake2.net/,