In recent years, with the proliferation of cloud computing technology, companies have increasingly adopted cloud services. In particular, the need for DX business in the software industry has led to an increase in job vacancies. The use of freelancers is a possible response to the shortage of jobs. An important consideration when a company chooses a freelancer is whether he or she can be trusted to get the job done on time. Such information cannot be derived from the submitted profile. This paper proposes a method to objectively assess the trustworthiness of freelancers. Moreover, a mechanism that prevents falsification of the evaluation is also considered. As a result, in the evaluation of the trust of freelancers, it was qualitatively shown that it is desirable to have a mechanism that prevents unauthorized use and falsification by applying digital signature with cloud environment to a third party's reference letter.