[curves] curve25519 public keys with high bit set

[CodesInChaos]

If you want to convince Curve25519 implementations to switch to
ignoring the last bit, convincing the NaCl authors is really
important. I expect most libraries to value compatibility with NaCl
more highly than the advantages of an ignored bit. My impression is
that where NaCl leads the other implementations follow.

So I think you should contact the NaCl authors. Since the most recent
version of SUPERCOP switched to ignoring the bit, they might have
already made this change to the upcoming NaCl version (Last December
they said that NaCl will probably be updated in 2014)

https://github.com/jedisct1/libsodium/issues/147