In 2015 we published the Simple Encrypted Arithmetic Library – SEAL, which is our attempt at building a publicly available and easy-to-use homomorphic encryption library. Since 2015 many improvements have been introduced to the library, and a new version SEAL v2.0 was released. Among other things, this update changed the underlying homomorphic encryption scheme to a more efficient one, introduced some optimizations to many core functionalities, and included some changes to the API to simplify the user experience.

Since the release of SEAL v2.0 several improvements have been made. Most of these are very important performance-related improvements, but there
are also a few changes and additions to the public API. These improvements have now been released as SEAL v2.1.

The present document is supposed to act as an introduction to SEAL v2.1 together with the extensively documented examples that come with the code. Extra effort is taken to explain the key differences to the previous versions of SEAL.

SEAL is freely available at http://sealcrypto.codeplex.com.