Balloon-BLAKE2b+HKDF KEM. [schemas/kem-balloon-blake2b-hkdf.tcl] Balloon memory-hardened password hasher must be used with BLAKE2b hash. => Balloon H = BLAKE2b KEK = HKDF-Expand(H, prk=balloon(H, passphrase, /kem/salt, s, t, p), info="cm/encrypted/balloon-blake2b-hkdf" || /id) "/kem/*/cek" is wrapped with [cm/keywrap/xchapoly] mechanism. => RFC 5869, HKDF => BLAKE2b is hashing algorithm => RFC 7693, same