Encrypting the future

SPECIAL REPORT | NSA pushes elliptic-curve cryptography to secure small devices and lend support to interoperable communication networks

If you go back 30 years, things weren't nearly as interoperable as they are now. ' DICKIE GEORGE, National Security Agency

GCN Photo by Rick Steele

The cryptographic security standards used in public-key infrastructures, RSA and Diffie-Hellman, were introduced in the 1970s. And although they haven't been cracked, their time could be running out.

That's one reason the National Security Agency wants to move to elliptic-curve cryptography (ECC) for cybersecurity by 2010, the year the National Institute of Standards and Technology plans to recommend all government agencies move to ECC, said Dickie George, technology director at NSA's information assurance directorate.

Another reason is that current standards would have to continually extend their key lengths to ensure security, which increases processing time and could make it difficult to secure small devices. ECC can provide greater security with shorter keys, experts say.

The switch to ECC will be neither quick nor painless. It will require mass replacement of hardware and software to be compatible with ECC and new NSA cybersecurity standards.

In fact, the 2010 goal might not be realistic for NSA, where more than a million different pieces of equipment will need to be moved to ECC, George said. NSA's move could potentially take as long as 10 years to complete, given the project's complexity and scope. The agency has not set a specific deadline for completing its Cryptographic Modernization initiative, started in 2001 and recognizes that cybersecurity will always be a moving target, he said. The move to ECC is part of the initiative.

ECC, a complex mathematical algorithm used to secure data in transit, will replace RSA and Diffie-Hellman because it can provide much greater security at a smaller key size. ECC takes less computational time and can be used to secure information on smaller machines, including cell phones, smart cards and wireless devices.

The specifics of the changeover were announced in 2005 with NSA's release of its Suite B Cryptography standards. Suite B falls under NSA's Cryptographic Modernization initiative and details ECC usage for public keys and digital signatures. The announcement, the first related to cryptographic standards in 30 years, was a watershed event, said Bill Lattin, chief technology officer at Certicom, a pioneer in ECC.

NSA has licensed approximately 25 of Certicom's ECC patents for use by the government and vendors that develop defense products.

The move to ECC represents a new way of doing business for the NSA. The Cryptographic Modernization initiative 'is not just replacing the old with the new. We are upgrading the entire way we do communications,' George said.

Interoperability is the core of the new communications program and the reason for the modernization initiative. NSA plans to work closely with other governments, U.S. departments and agencies, first responders, and the commercial sector, George said. To do so, the agency needs public-key algorithms to securely transmit information among all parties, he said.

'If you go back 30 years, things weren't nearly as interoperable as they are now. In today's world, everything is being networked. We have to allow interoperability. And the cryptography has to match [among devices] because if it doesn't, it is not going to be interoperable,' George said.

These interoperability goals will most likely extend across federal, state and local governments in addition to law enforcement agencies nationwide.

Although RSA and Diffie-Hellman are both public-key algorithms, experts say they don't scale well for the future. To make RSA and Diffie-Hellman keys, which now can go to 1,024 bits, secure for the next 10 to 20 years, organizations would have to expand to key lengths of at least 2,048 bits, said Stephen Kent, chief scientist at BBN Technologies. Eventually, key sizes would need to expand to 4,096 bits. 'That's enormous keys. To do the math operations underlying the keys takes longer and is more computationally intensive,' Kent said.

Thus, NSA's decision to move to ECC, which appears to be the only option. Experts agree that there is no new technology comparable to ECC. Although there are a number of protocols, there are only two basic technology approaches, George said: integers, used by RSA and Diffie-Hellman, and ECC, he said.

'ECC is the only impressive thing out there,' Kent said. 'People don't get excited every time a new thing comes along. We wait several years and let people try to crack it first. ECC definitely passed the test in this regard.'

NIST, which develops government- wide cybersecurity standards, also sees a need to move to ECC, although its recommendations are less stringent than NSA's, whose ECC guidelines are a subset of NIST's.

'I'm pretty sure [RSA and Diffie-Hellman] will be broken within a decade or so,' said Bill Burr, manager of NIST's security technology group. 'We are trying to end the use for most purposes of RSA and Diffie-Hellman with 1,000-bit keys by the end of 2010. And if you are real conservative, we are late.'.

'NSA has been fairly aggressive to standardize on ECC,' Burr said. We are slower, partly because we think it will naturally happen anyhow.'

John Pescatore, vice president and analyst at Gartner, does not see a need for the average user to switch to ECC unless it is to take advantage of its smaller size, such as securing cell phones and smart cards. With NSA, those technologies might include 'things that a soldier carries around'and [has] strict limits on power consumption,' Pescatore said.

Burr expects ECC to become a universal standard by 2020, when most ECC patents owned by Certicom expire. 'If it's not a big problem today, it may be hard for the CIO to motivate people to transition to ECC,' said Kent.

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