Develop a library in C

Programmer services are required. A library in C is needed (C++ elements are possible, but the implementation should be functional, not object-oriented), implementing Asmuth-Bloom secret-sharing (CPS) scheme in a ring of integers.
The implementation should include all used algorithms in the form of source codes (working with large numbers, number-theoretical algorithms, etc.).
It is possible to use third-party libraries (open source), while the source code of the parts of the libraries used in the project should be included in the project, with the exception of all unused parts.
The CPC library must handle secrets of 128, 196 and 256 bits.
The implementation of the CPC library should be platform independent.
As an example of the implementation of such a scheme and an example of the library interface, one can consider the implementation of the Asmuth-Bloom scheme in the polynomial ring from the Bee2 library.

The proposed general procedure for the development of the library is as follows:
1. Development and coordination of requirements for the library (reference model of implementation, interface, etc.); testing methods and criteria for completion of work; definition of work stages; evaluation of work terms; evaluation of the cost of work;
2. Development and coordination of the internal design of the library (composition of functions, their interfaces, data structure, etc.), clarification of the phased work;
3. Development of the library program code (phased development);
4. Testing and delivery of work (phased).

The requirement for the developer is the presence of experience in programming theoretical and number problems.

The language of communication is Russian.

Additional Notes – Interest in Completed
A library of CPS, not a separate stage. In this regard, an acceptable payment scheme will encourage the developer to complete the task.