Some communication vulnerabilities, such as cryptographic keys generated by a random number generator, have been identified during evacuation and recovery activities of a disaster. Due to some disfunctions of infrastructures and lack of guardiancies, sensitive data and illegal transactions may have occurred uncontrollable. One of the main causes of those communication vulnerabilities is the existence of the Random Number Generator (RNG) within the cryptosystem of network transaction with minimum infrastructures. The communication protection through cryptography cannot access the true RNG as it requires sophisticated and costly devices. To handle the situation, this research has investigated the Software-based True Random Number Generator (STRNG). In contrast to other TRNGs, the STRNG can be deployed using minimum capabilities of a processor, such as a Raspberry Pi. The technology can still generate high-entropy random numbers of unlimited number of digits, and the random number generator bitrate can reach up to 3 kbps. With the STRNG the communication can benefit it for the cryptography that will protect the communication from adversaries. Such secure communication will reduce the capability of potential adversaries that allowed by disaster have a bigger possibility to attack due to the communication vulnerabilities. As part of the bigger research scope, the positive results of the STRNG technology will then increase the quality of the whole framework of the Resilient Urban Development (RUD) project.