Since the last few years, the adoption of cryptocurrencies by the general population has been steadily increasing. However, a high technical barrier to entry remains for the average user to successfully and securely conduct transactions. In order to continue to drive the mass adoption of cryptocurrencies, it is necessary to offer a simpler and more fail-safe way to conduct transactions than is currently possible via ordinary wallets.

The blockchain project Dash is currently developing Dash Platform, an approach for realizing decentralized applications. In contrast to better-known projects such as Ethereum, in which smart contracts are realized through program code on the blockchain, Dash relies on a data-oriented approach (data contracts). This means that the application logic is outsourced to the clients, while the application data is stored in a separate blockchain.

In this paper, the technology behind Dash Platform is presented on the basis of DashPay. It also covers the basic building blocks that make DashPay possible, such as identities and the Dash Platform Name Service (DPNS). DashPay is a data contract in which users can uniquely identify themselves via a username and send contact requests to each other. Contacts can thus establish bidirectional, direct payment channels between each other. DashPay thus enables simple, fast and secure payments via the Dash network. DashPay users will no longer need to exchange long and confusing public addresses in order to process payments with their contacts.

We investigate the security of the cryptocurrency Bitcoin and deal with both the security principle of this new type of currency and the associated security risks for end users.

This paper deals with attacks on the payment network itself, such as DoS attacks, Sybil attacks, the 51% attack in its various forms, and game-theoretic attacks, as well as risks for the end user when using Bitcoin in everyday life and problems with their privacy and the risks that a decentralized system entails. A decentralized system is in its nature transparent to all participants, and it can be assumed that governments, intelligence agencies and criminals also try to gain influence here.

The aim of this paper is to find out how Bitcoin compares to traditional centralized payment systems in terms of security and whether new attacks and problems emerge with the decentralization, which could undermine the network or reveal the pseudonymous payment participants.