Here is a list of all documented files with brief descriptions:

djcs.h	The Damgard-Jurik scheme is a scheme which provides homomorphic addition, and limited multiplication on encrypted data
djcs_t.h	The threshold Damgard-Jurik scheme is a generalization of the Paillier cryptoscheme, but with an increased ciphertext space
egcs.h	The ElGamal scheme is a scheme which provides homormophic multiplication
hcs_random.h	Provides secure random state for use in functions which require random values
hcs_shares.h	This is a structure which is designed to hold a number of shares
pcs.h	The Paillier scheme is a scheme which provides homormorphic addition, and limited multiplication on encrypted data
pcs_t.h	The threshold Paillier scheme offers the same properties as the Paillier scheme, with the extra security that decryption is split performed between a number of parties instead of just a single trusted party