Introductoryly we theoretically defined e-commerce, shopping in web stores through the customer's perspective, recognise data that pose a risk, analyze ways in which the customer can protect their data and define ways in which the seller protect the customer. After that we explore ways in which a password can be protected in databases, in a way that no one can breach protection even though they have full access to the databases. With Hash function we graphically showed how are passwords stored in databases. In the experimental part of the work, the entire purchase process in the web shop is carried out, from the creation of a user account where personal data are entered, through the selection of payment methods and delivery to the final online payment. This is followed by a focus on the European Data Protection Regulation on the protection of personal data, how it is applied, what its purpose is and how the user needs to react in case of data breach. The purpose and goal of this final paper is to get acquainted with the risks of Internet commerce, ways of data protection by sellers, security of online card payements , security of users profile password, data security of the entire purchase process, data breaches and institutions tasked with monitoring and responding to data breaches.