logi.crypto 1.1.2 is a pure java crpyto package downloadable from http://www.logi.org/logi.crypto/
logi.crypto heavily uses java.math.BigInteger and i found quite a lot of difficult to track bugs with it. Drawback: It uses lots of Random stuff so reproducebility is not always given. Run a few times to be sure.
I ran the following tests:
cacao -cp logi.crypto1.1.2-test.jar:logi.crypto1.1.2.jar org.logi.crypto.test.TestIterate cacao -cp logi.crypto1.1.2-test.jar:logi.crypto1.1.2.jar org.logi.crypto.test.TestSecretShare Xor cacao -cp logi.crypto1.1.2-test.jar:logi.crypto1.1.2.jar org.logi.crypto.test.TestSecretShare Poly