It's now possible to multiply Cypher by an integer.
Paillier is a homomorphic encryption scheme, where an encrypted
plaintext `m` raised to an integer `k` will decrypt to the product of
the plaintext `m` and `k`.
Function `EncryptWithR` lets to specify randomness `r` explicitely. For
some ZKPs based on the Paillier scheme, it's required to use the same
`r` for encryption and constructing ZKP. It wasn't possible previously,
because `r` was generated internally and never returned.
I did not want to modify `Encrypt` to return `r` because it would break
existing code using this API, as well as, I want to make sure person
using the specific `r` and using it somewhere else really knows what
he's doing.
`PublicKey.Add` accepts now an arbitrary number of `*Cypher`s.
Previously, it was possible to add only two `*Cypher*` instances and it
was quite unwieldy for a lot of use cases.
The current implementation is backward compatible. It's still possible
to pass just two `*Cypher` arguments, so every project referencing the
library will observe no compilation issues.
Piotr Dyraga