[kushti]

Curve25519 implementation was taken from the internet. The problem I see with all the Java implementations of it, they're not reviewed by professional cryptographers. This is one the reasons why Scorex isn't production-ready.

RIPEMD implementation was taken from the internet too.

[j-m-o]

That Curve25519 implementation is by Moxie Marlinspike, and that RipeMD160 algorithm is built into BouncyCastle.

There may still be attack vectors on them, but that's about as close to "reviewed by professional cryptographers" as you're likely to get at this point.