A novel Physically Unclonable Functions (PUF)-based keyless encapsulation protocol was recently proposed by our team that does not rely on cryptographic keys and directly encrypts the messages using the unique responses extracted from embedded ReRAM PUFs in the devices. Therefore, this method avoids challenges and security threats due to key storage and distribution. Since this protocol uses analog resistance values from ReRAM PUFs for message encryption, the protocol is sensitive to variations in PUF responses due to environmental conditions. Therefore, it requires schemes to minimize the impact of such variations to guarantee the integrity of the decryption of the message. In this paper, we develop protocols to utilize Error Correction Coding (ECC) mechanisms to stabilize the cipher text encrypted with this protocol. The ECC-based key encapsulation protocol was evaluated using Reed-Solomon and BCH codes. The results show the effectiveness of the proposed protocol in offering noise-free messages under common ranges of environmental variations in ReRAM PUF responses.