A Reliable and Universal Cloud Wallet

Implementation of a universal and reliable cloud wallet.
This document explains the design, implementation and deployment of a secure Ethereum wallet backed up by a vault of secrets on the cloud. It also introduces key concepts for this task in the field of cryptography and cybersecurity. This project is done in collaboration with the European H2020 i3-Market project. Intelligent, Interoperable, Integrative and deployable open source MARKETplace with trusted and secure software tools for incentivizing the industry data economy. Within this project, the development of a vault of secrets, such as a secure wallet on the cloud, is essential if we desire a trusted data-exchange environment backed up by the blockchain. The developed solution, named Cloud Wallet, consists of three pieces of code, each of which, serves a specific purpose within the complete project: ? Frontend Application (CloudWalletApp) ? Client Library (CloudWalletClient) ? Backend Server (CloudWalletServer) On the one hand, the frontend app allows the user to intuitively create and import Ethereum accounts in order to sign raw messages or Ethereum transactions. While the client takes care of the setup and communication with the server (among others) the app works as a UI wrapper made with the React framework for this client. To sum up, the app manages user interactions, renders the website, and uses CloudWalletClient to manage blockchain and interact with the server. On the other one, CloudWalletServer safely stores an encrypted representation of account credentials so that the client used on the application can rely on a secure credentials cloud backup to restore them back to the client in case of incidences (i.e. lost device). Additionally, it uses Key Derivation Functions to deliberately slow password-check processes and makes them expensive in terms of CPU and memory in order to discourage pre-computation attacks. This project has been developed in conjunction with Alberto Miras Gil with our university and tutor?s approval. Even though we have worked on t