EMV® Chip Specifications To Support Elliptic Curve Cryptography

Cryptography standard enables robust EMV® Contact Chip security long-term as payment technology evolves Frequently Asked Questions (FAQ) 1. What has EMVCo published? Specification Bulletin 243[1] to enable the use of Elliptic Curve Cryptography (ECC) for EMV Contact Chip payment transactions has been published following approval of its release by EMVCo’s Board of Advisors. 2. What is ECC and why is EMVCo incorporating it into its specifications? In an EMV Contact Chip payment, the merchant POS terminal can cryptographically authenticate a card and its data by verifying digital signatures generated by the card, its issuer and the payment system. Since its inception, the EMV Contact Chip Specification has used RSA (Rivest-Shamir-Adleman) public key cryptography whose security depends on the so-called factorisation problem. This has proven to be robust and provides strong security. ECC is another form of public key cryptography based on the algebraic structure of elliptic curves over finite fields. While ECC and RSA can each be used to secure transactions, ECC can be used with much smaller key sizes due to its greater security efficiency when compared to RSA. The size of a cryptographic key is important. As a general rule, the longer the key the more storage and processing power required. EMVCo recognises that RSA could continue to be used with longer and therefore ‘stronger’ keys over time; however, the increase in key length increases computing time making transaction times slower. In contrast, ECC is compact and efficient, which makes it an appealing option for use in devices with limited storage and processing capabilities, and where transaction speed is important. EMVCo publishes Specification Bulletins[1] as and when required to detail and confirm changes to the EMV Specifications. Over time, once a number of updates have been made, an editorial update is undertaken to include the bulletins into the larger specification document. SB 243 is to be incorporated in the Contact Card Specification v4.4. 3. What benefit does ECC bring to the wider payment community? ECC enables the payment community to achieve security without impacting technical performance, constraining payment innovations or restricting existing and new transaction scenarios. It is a particularly appealing option for use in devices with limited storage and processing power. ECC achieves this efficiency and scalability over the more conventional RSA public key cryptography, while minimising changes to the overarching key management infrastructure. It also provides the EMV community with a state-of-the-art security standard that will evolve in line with new technologies and has the ability to support the long-term needs of EMV Specifications. 4. Will this make contact payments more secure? No. ECC doesn’t necessarily make payments more secure than today. It does, however, enable robust security to be maintained as payment technology advances and innovates, due to the possibilities presented by the small key lengths and digital signatures. It is also important to note that the payment community approaches security in ‘layers’, using many different techniques to combat fraud. Cryptography is just one of these layers of protection. 5. Why is EMVCo introducing ECC now? EMVCo continually evaluates its security offering and monitors developments within the industry. In 2010, the U.S. National Institute of Standards and Technology (NIST) announced that it would not support the use of EMV’s longest RSA 1984-bit key length after 2030. EMVCo works to align with other bodies and identified that it was important to provide a security roadmap that supports the long-term security needs of the wider industry. It has taken EMVCo time to not only include the technical details of the ECC standard, but also identify how best to incorporate it into the future of EMV Chip technology offering. 6. Will