Brad Garlinghouse, chief executive officer of blockchain-payments firm Ripple, has been asked to appear before the U.S. Senate to give evidence on proposed federal legislation governing digital assets. His testimony will place one of the cryptocurrency sector’s most prominent executives at the center of Washington’s effort to craft a comprehensive regulatory framework for the industry. Lawmakers are accelerating work on new rules aimed at clarifying the legal status of tokens, licensing requirements for trading platforms and safeguards for retail investors. Garlinghouse’s appearance signals that senators want direct input from companies operating major blockchain networks as they debate how to balance innovation with consumer protection and financial-crime controls.