Portal: Micropayments on the Paywalled Internet

Abstract

In this work, we propose and evaluate Portal, a payment protocol and software system that enables one-click purchases of long-form news content on the Internet, without requiring a user to sign up for a subscription or login to a content provider’s website. The payment protocol enables clients to purchase a digital good (e.g. a single news article) via a standard payment mechanism, such as PayPal or a credit card, and then claim the good from the content provider over an unauthenticated HTTP channel by providing a valid proof-of-payment. This proof demonstrates that 1) a payment transaction of sufficient value was issued for the particular good being claimed (article id verification), and 2) the identity of the payer matches the identity of the client claiming the good (user id verification). Our proposed client-side software handles the construction and provision of this proof, taking the place of manual, password-based authentication.Our research is motivated by the failure of most news sites to convert a significant percentageof their online readership base to paying subscribers, and various identified shortcomings in thepaid subscription model. We present the technical architecture for an alternate monetization system, which allows the purchase of web content on a case-by-case basis, does not lock readers in to a long-standing contract, and does not stipulate that users log in to purchase and read an article discovered while browsing the web. After detailing the payment protocol underling our proposed system, we discuss our particular software implementation, with a focus on key design choices, such as the use of PayPal as a central transaction data store, verified email addresses as universal user identifiers, and client-side certificates for user authentication.We conclude by evaluating our system on the basis of usability concerns, privacy and securityconsiderations, and questions of adoption and scalability. We then outline key facets of a deployment and launch plan for Portal, ending with a discussion on potential avenues for future work.