IP trace back plays an important role in internet cyber investigation processes, where the sources and paths of packets need to be identified the traversed path. It has a wide range of applications, including forensics network, auditing security, network fault diagnosis, and performance testing. Despite a plethora of research on IP trace back, the Internet is yet to see a large-scale practical deployment of trace back. While this makes the trace back service more available, regulating access to trace back service in a cloud- based architecture becomes an important issue. Consequently, we address the access control problem in cloud-based trace back. Our design objective is to check illegitimate users from requesting trace back information for malicious intentions such as ISPs topology discovery. To this end, we propose a temporal token- based authentication framework, called FACT, for authenticating trace back service queries. FACT embeds temporal access tokens in traffic flows, and then delivers them to end-hosts in an efficient manner. The proposed solution ensures that the entity requesting for trace back service is an actual recipient of the packets to be traced.