The explosion in mobile communication use in our lives has led to a new method for information exchange between people. Therefore, there are now plenty of instant messaging applications, which have a single purpose that is done through different methods. Thus, methods and information exchange protocols play an important role in reducing processing times, low battery consumption and low bandwidth consumption. This article shows the comparison in time performance of an instant messager server through two open source cryptographic library implementations, using two asymmetric cryptographic processes in a centralized messaging system in order to seek confidentiality, integrity and authenticity of the messages. Cryptographic schemes used are Elliptic Curve Diffie-Hellman (ECDH) and Elliptic Curve Digital Signature Algorithm (ECDSA). In addition, it determines which library is more efficient to implement in that server.