Consideration of Attribute-Based Encryption Utilization in IoT Communication

While Internet-of-Things (IoT) devices enable the collection of large amounts of data, highly confidential data must be protected as it is transmitted between them and servers. The publisher/subscriber model via a broker is widely used for IoT communication on the Internet, and TLS protects data during communication. Since all data is temporarily stored on the broker, it faces a high risk of attacks. Therefore, the data transmitted to the broker must be encrypted, and access to the IoT data for brokers and subscribers must also be controlled. Attribute-based encryption (ABE), which enables fine-grained access control, has been widely studied due to its suitability for IoT applications. However, ABE processing is computationally intensive for resource-constrained devices. To accelerate the encryption process, this paper proposes an ABE encryption method that modifies the Key Encapsulation Mechanism. This involves enabling the continuous use of the same symmetric key for a specific period, provided it can be securely shared with a trusted party over TLS communication. It is established that the feasibility of speeding up ABE encryption under limited circumstances is viable. Moreover, our analysis suggests that an appropriate symmetric key validity period should be established, taking into account both security and performance aspects.