Grin core developer David Burkett released the project's December progress report on December 29. After several months of planning, the development of Mimblewinble extension module has officially started. In December, the work was mainly focused on reorganizing the core sharing between Grin ++ and LTC. Logically, it involves all logging, serialization, encryption, error handling, and common data structures (headers / blocks / transactions), most of which is written for Grin ++. In addition, David Burkett also released the work plan for January 2020, including: 1. Determine the build method: Since the code will now be distributed in several repositories, it will require a slightly more complicated build process, and currently tends to use libbitcoin to build the system A simplified version of; 2. Define all LTC models: determine the exact fields and serialization format of the header and kernel (including signatures); 3. move the database implementation to libmw-core, clean up to match the new standard, and add the complete Testing; 4. In January 2020, a faster synchronization mechanism will be developed for Grin, and LTC will directly benefit from it.