I love the Go language. In fact, I have dumped C++ for most of my executable code, and now just use Go. Overall it is a simple, yet powerful, language and which produces robust, fast and powerful code. If you want any kind of library, it just connects to GitHub, and downloads the code in a simple to use form. For cryptography, it is one of the best languages around, as produces robust code, and which integrates most of the modern standards (such as RSA and Elliptic Curve for public key and AES for symmetric key encryption).