The reputation algorithm is the main feature of the proposal because, thanks to it, the user can use a quantitative measure to decide whether to trust another user or not. The algorithm is based on the theory of six degrees of separation and individual scores within our platform. This number of steps may be reduced significantly by introducing the concept of social networks. Our application uses social networks when logging into the application to create a network of user, which is used to interconnect users and provide a reliable measure of confidence among them. Through the use of social networks, the six degrees of separation can be reduced on average to less than four. In particular, according to several studies on Facebook , the average distance is 3.9, corresponding to intermediaries or ’degrees of separation’, which shows that the world is even smaller than expected.