# A Blockchain Self-Sovereign Identity for Open Banking Secured by the Customer's Banking Cards
## 2 Background  
The user-centric model, and now the SSI approach, are consequences of the revolution of identity management from centralized silos to a federated model. These imply the principals of returning the control of identity data to their owners, as stated by [PERSON] and [PERSON] and [PERSON] (2008). The self-sovereign identity principals [PERSON] and [PERSON] (2008) include:  
* Users must have an independent existence;
* Users must control their identities;
* Users must have access to their own data;
* Systems and algorithms must be transparent;
* Identities must be long-lived;
* Information and services about identity must be transportable;
* Identities should be as widely used as possible;
* Users must agree to the use of their identity;
* Disclosure of claims must be minimized.  
SSI systems based on Blockchain have the means to deploy the concept of identity and benefit from the rich characteristics provided by Blockchain, such as immunity, cryptographic data storage, distributed key management, and distributed storage ([PERSON], 2010). SSI returns the control over identity information storage and selective disclosure rights to the identity owner. It enables the decentralized architecture to minimize the probability of data leakage that may be caused by compromising centralized identity repositories. In addition, combining SSI with Blockchain provides data consistency, availability, and privacy, and reduces correlation by creating a unique identifier for each service.  
The aim of Blockchain is to store cryptographic transactions in a public ledger based on a decentralized consensus mechanism, which is hard to break or modify, according to the investigation results from ([PERSON], 2010). Our proposed platform utilizes the Ethereum public ledger to record the identity transaction hashes, to prevent hacking, denial of service attacks, and identity theft or loss. In addition, it enables smart contracts, which allow multiple benefits such as automation of approved financial services and integration with decentralized applications.  
uPort (2012, 2013) is an identity system implementation based on Decentralized Identifier (DID) specifications and W3C (2013), and relies on Ethereum Blockchain to deploy several smart contracts to manage identities, attributes, and attestations of attributes. It allows selective disclosure and sharing of identity attributes between the user and related parties. Public data are stored in the Interplanetary File System (IPFS) (2013); the public key is bound to a hash link that points to public profile data in the IPFS of Ethereum Blockchain. Only users who own the private key and the data hash on the IPFS, which ensures the integrity, can modify this link. This work does not use the uPort app since it was decommissioned in June 2021 and replaced by the Veramo framework (2013).  
Veramo Veramo Veramo (2013, 2014); (2014) is a new and evolving iteration of uPort. It provides open source libraries for a modular API for SSI and verifiable data, creating and managing interoperable DID and Verifiable Credentials (VCs) (2014) without relying on third-party vendors or centralized systems. It supports many platforms, such as Node, browsers, and React Native. Veramo is fitted to our framework and banking use case as a middle layer to control DID and VCs.