What If the Cryptography Underlying the Internet Fell Apart?

By Roberta Faux, Director of Research, Envieta

Without the encryption used to secure passwords for logging in to services like Paypal, Gmail, or Facebook, a user is left vulnerable to attack. Online security is becoming fundamental to life in the 21^st century. Once quantum computing is achieved, all the secret keys we use to secure our online life are in jeopardy.

The CSA Quantum-Safe Security Working Group has produced a new primer on the future of cryptography. This paper, “The State of Post-Quantum Cryptography,” is aimed at helping non-technical corporate executives understand what the impact of quantum computers on today’s security infrastructure will be.

Some topics covered include:

–What Is Post-Quantum Cryptography

–Breaking Public Key Cryptography

–Key Exchange & Digital Signatures

–Quantum Safe Alternative

–Transition Planning for Quantum-Resistant Future

Quantum Computers Are Coming

Google, Microsoft, IBM, and Intel, as well as numerous well-funded startups, are making significant progress toward quantum computers. Scientists around the world are investigating a variety of technologies to make quantum computers real. While no one is sure when (or even if) quantum computers will be created, some experts believe that within 10 years a quantum computer capable of breaking today’s cryptography could exist.

Effects on Global Public Key Infrastructure

Quantum computing strikes at the heart of the security of the global public key infrastructure (PKI). PKI establishes secure keys for bidirectional encrypted communications over an insecure network. PKI authenticates the identity of information senders and receivers, as well as protects data from manipulation. The two primary public key algorithms used in the global PKI are RSA and Elliptic Curve Cryptography. A quantum computer would easily break these algorithms.

The security of these algorithms is based on intractably hard mathematical problems in number theory. However, they are only intractable for a classical computer, where bits can have only one value (a 1 or a 0). In a quantum computer, where k bits represent not one but 2^k values, RSA and Elliptic Curve cryptography can be solved in polynomial time using an algorithm called Shor’s algorithm. If quantum computers can scale to work on even tens of thousands of bits, today’s public key cryptography becomes immediately insecure.

Post-Quantum Cryptography

Fortunately, there are cryptographically hard problems that are believed to be secure even from quantum attacks. These crypto-systems are known as post-quantum or quantum-resistant cryptography. In recent years, post-quantum cryptography has received an increasing amount of attention in academic communities as well as from industry. Cryptographers have been designing new algorithms to provide quantum-safe security.

Proposed algorithms are based on a number of underlying hard problems widely believed to be resistant to attacks even with quantum computers. These fall into the following classes:

• Multivariate cryptography
• Hash-based cryptography
• Code-based cryptography
• Supersingular elliptic curve isogeny cryptography

Our new white paper explains the pros and cons of the various classes for post-quantum cryptography. Most post-quantum algorithms will require significantly larger key sizes than existing public key algorithms which may pose unanticipated issues such as compatibility with some protocols. Bandwidth will need to increase for key establishment and signatures. These larger key sizes also mean more storage inside a device.

Cryptographic Standards

Cryptography is typically implemented according to a standard. Standard organizations around the globe are advising stakeholders to plan for the future. In 2015, the U.S. National Security Agency posted a notice urging the need to plan for the replacement of current public key cryptography with quantum-resistant cryptography. While there are quantum-safe algorithms available today, standards are still being put in place.

Standard organizations such as ETSI, IETF, ISO, and X9 are all working on recommendations. The U.S. National Institute for Standards and Technology, known as NIST, is currently working on a project to produce a draft standard of a suite of quantum resistant algorithms in the 2022-2024 timeframe. This is a challenging process which has attracted worldwide debate. Various algorithms have advantages and disadvantages with respect to computation, key sizes and degree of confidence. These factors need to be evaluated against the target environment.

Cryptographic Transition Planning

One of the most important issues that the paper underscores, is the need to being planning for cryptographic transition to migrate from existing public key cryptography to post-quantum cryptography. Now is the time to vigorously investigate the wide range of post quantum cryptographic algorithms and find the best ones for use in the future. This point is vital for corporate leaders to understand and begin transition planning now.

The white paper, “The State of Post-Quantum Cryptography,” was released by CSA Quantum-Safe Security Working Group. This introduces non-technical executives to the current and evolving landscape in cryptographic security.

Download the paper now.