## 4 Results and Discussion
### Remarks on the Identified Challenges  
While the future of mobile payment technologies may be bright, many challenges must still be overcome. The challenges of digital payment technologies found in this review are categorized under five key themes (see Figure 5). The majority of the studies (39%) covered the technical challenges in digital payment technologies (32 studies). As pointed out by [PERSON] and [PERSON] [44], this is mainly because there has been a significant change in the means of making and receiving payments and that the number of modes of payments has been increased substantially due to technological infrastructure and policy changes.  
The technical challenges in _privacy, security and lack of technical infrastructure_ were cited the most in some studies (e.g., [8, 37, 44, 55, 72]). It was evident that consumers face security problems and poor network connectivity issues while making cashless transactions [44]. Similarly, their lack of awareness in existing security controls causes vulnerabilities in payment technologies, which severely compromise the users' privacy and users' data communications [72]. Thus, it is crucial to incorporate smart security features technically into the payment systems, so that the users can use digital payment technologies without the fear of security and privacy threats. Furthermore, it was confirmed that privacy and security factors influence payment technologies amongst micro, small and medium enterprises [55]. Additionally, an assessment of country-level privacy risk for digital payment systems highlighted the privacy risks from cyberattacks and the threat of data misuse from the analysis of mobile wallets and remittance privacy policies [8].  
The social challenges were mentioned in 20 studies, which constituted 25% of the articles reviewed. Although the social challenges of digital payment technologies cover various social aspects, most studies discussed 'trust' as the core challenge associated with payment technologies. It is important to note that digital payments are not simply about technology. The social aspects play a vital role for consumers. Many studies (e.g., [11; 14; 69]) highlighted the 'trust issues' in digital payment technology adoption, which involves consideration, such as how consumers react to payment technologies and how comfortable they feel with transacting digitally. Most findings suggested that the intention to use digital payments was determined by the perceived ease of usage, perceived usefulness, attitude towards digital payment and, particularly, by trust [11]. For example, millennials' choice of payment technologies depends on how much they trust the ability of digital payment technologies to protect their privacy. Thus, their faith depends on the reputation of the payment technology [69]. Similarly, a lack of trust in regulation is one of the main challenges faced by small retail stores in the context of adopting digital payment technologies [14].  
From the consumer perspective, the economic challenges caused by digital payment technologies are mostly concerned with the cost of using the technology itself [62; 82]. Compared to handling cash, which does not cost anything for consumers, digital payment technologies, such as digital wallets from banks, incurred monthly fees for simply using the payment technology. Another economic issue that comes to the fore is the problem of inflation rate caused by the high volatility of cryptocurrencies resulting in speculative markets.  
The awareness challenges highlighted a lack of digital literacy and awareness about digital payments that discouraged people from using digital payment technologies [13; 57]. Similarly, legal challenges concern the legitimacy of cryptocurrencies, such as Bitcoin, which completely decentralized the digital payment system and revolutionized financial markets.