# Development of an Electronic Smart Safe Box Using Private Blockchain Technology
## 2 Literature Review  
In this era of the IoT, connectivity and network communication are largely exposed to a number of security attacks. Similarly, smart home devices such as safe boxes need robust security solutions based on blockchain and other relevant solutions [3; 4; 5]. In this regard, several previous researchers have presented several smart safe box securities and IoT mechanisms [6; 7]. In a research work presented in [8], the authors developed a smart safe prototype based on IoT architecture with face and fingerprint recognition. They used specifically some features like personal identification number (PIN) code, two-way verification, and face recognition fingerprint. Due to limited security options, the safe box is vulnerable to various security attacks such as shoulder, physical, etc. In order to provide a guard against a physical attack, the authors propose a system as presented in [9] using a remote tracking security box with a multi-factor authentication system. The designed security box can be tracked remotely. In addition, they implement a biometric fingerprint sensor and notify when the security box arrives at the base station. The work presented in [10] represents an automatic safe deposit box security system using Arduino Uno. A safe box with a security system and a microcontroller using the Arduino Uno contains features such as a buzzer, password keypad, and a fingerprint. They also thoroughly list the advantages and disadvantages of fingerprint mechanisms. However, the safe box is vulnerable to relocating attacks as the system does not provide a GPS tracking system. Similar research is performed in [11] to overcome the limitation in the article [10], by adding a global system for mobile communication (GSM) module to enhance the smart safe box's security. Any attempt to relocate the smart safe box activates the GSM module which sends an SMS message to the authorized user. This works as a successfully executed SMS-based system in the smart box. This potential smart safe box can be used for personal and commercial purposes. However, this research relies on the availability of the internet. Thus, if there is no internet, the user cannot access the device. The LockerSwarm [12] is a smart locker solution that can be used as a public locker in universities. These public lockers use the Arduino to design a smart lock that is used with a control of the electric door's lock. Also, they use a Quick Response (QR) code that allows users to manage their lockers through the messaging app. The users can also share access to the locker with other colleagues or friends. Further, the LockerSwarm allows a system administrator to monitor and control all safes. Following the approach presented in [12], a survey of various types of smart lockers is presented in [13]. The authors identified a number of problems in designing a smart locker system and the possible solutions to overcome these problems. The authors also classified a number of areas where the smart locker can help in keeping information and documents safe from any possible type of security attack. However, the smart locker system presented in the survey is mainly related to how to avoid physical attacks. Face recognition and One Time Password (OTP) are proposed in [14; 15], where a locker system is installed with face recognition using an OTP service which is sent to the user via SMS and GPS. Typing the locker PIN is allowed with three attempts. However, this research does not use fingerprints to give access to the user. Also, the transaction to the smart safe box is not recorded which may reduce trust among the users of the safe box. In order to record the transactions for safety purposes, blockchain technology has recently been introduced [16; 17; 18]. Similarly, blockchain technology has recently been researched for providing security to IoT systems.