Along with a lack of prudent digital asset evaluation frameworks and a shortage of variety for digital assets, security is another issue of top concern for investors. On the one hand, security is still a challenging issue for blockchains on the infrastructure layer. Cryptocurrencies may suffer from different attacks such as “51% Attack”, threatening the integrity of and the foundation upon which the trust and consensus of blockchain technology are built. For example, Verge, a cryptocurrency for users who value security and privacy, suffered from a “51% attack” due to a bug in its codes. As a consequence, its price dropped by 15% within 24 hours after the attack.