There is no doubt that nowadays, the use of smartphones for communication between two or more entities through instant messaging applications has become a trend model in our society. New messaging applications started to emerge and try to replace traditional SMS. In fact, they have become the main communication route, and it is almost impossible to find someone who does not use at least one of these kinds of messaging applications. However, building them with security and privacy in mind of developers was not important in the beginning. In other words, when the popular messaging applications were created, they did not support end-to-end encryption, only standard client-to-server encryption, which gave the service providers access to more private information than necessary. Additionally, information that is exchanged in such instant messaging applications has the characteristic to be sensible that results in the necessity to achieve security services associated with users information, by achieving confidentiality, integrity, and authenticity in sent and received messages. In this article, we present a security verification on the Signal and MTProto 2.0 cryptographic protocols, which are contained in the most commonly used instant messaging applications. The security verification is made by using automatic verification tools and obtained results show that the protocols are flawless in terms of their construction, message delivery logic, and semantics. In other words, they are safe from attacks that automatic protocol verification tools check for.