The broad adoption of smartphones in the U.S. and increased willingness of consumers to use their mobile phones to make e-commerce purchases has incented merchants to expand their online card-not-present (CNP) businesses to the mobile channel., At the same time, U.S. issuers and merchants are migrating to EMV chip cards at POS to reduce counterfeit card fraud, which is driving fraud to the less secure online and mobile channels. All of these factors together emphasize the need for stronger security controls to manage the growing CNP fraud. Tools exist today to address some CNP risks, particularly around authentication, which has been a long-standing primary challenge to the industry. This brief discusses the pros and cons of one tool – the 3-Domain Secure (3DS) authentication messaging protocol, comparing the initial 3DS version 1.0 to the new 3DS 2.0 version, and why the time is right for the U.S. issuers and merchants to adopt it.