The swarm attestation methods have been proposed to detect illegitimate modifications in a large network efficiently. However, they do not provide the scalable identification of detected devices, which is critical to keep a swarm network trustworthy in the practical uses. In this paper, we propose a lightweight attestation method with efficient scalable identification of target devices. The proposed approach, called (Collective Attestation for Manageable IoT Environments), combines binary-embedded tag generation and regional reports to build the region-based attestation result. During the attestation process, the swarm network generates merged region summaries. An authorized verifier can infer the individual device information from the regional attestation results. In this way, can achieve the scalable identification of compromised devices with significantly less overhead.