Double lasts longer - How companies can manage strong authentication intelligently
More and more companies are taking advantage of the possibilities offered by connecting external employees, customers and business partners to their corporate networks via the internet, making important information available to them. Users generally log on to corporate networks or applications with a username and a static password. But in the aftermath of the most recent phishing attacks, many companies no longer consider this type of authentication sufficient for their needs. The point is that if a third party gets hold of this access data, there is almost no way of checking who is actually logging on accessing corporate data.
Since the dramatic increase in fraudulent online activities, static passwords and usernames often offer inadequate security for access to corporate networks. The most recent phishing attacks have shown how professional internet fraudsters steal passwords and identities. To exclude the growing security risk, experts recommend dual-factor authentication – also known as “strong” authentication. The use of security systems for strong authentication practically excludes the risk of passwords being deliberately stolen or cracked. This is by virtue of the fact that strong authentication extends the “knowledge” factor – in other words the password – by the “ownership” principle – mostly in the form of a security token or a smart card. In principle therefore, strong authentication is based on a principle familiar from EC cards as used in ATMs: card plus PIN code – ownership plus knowledge.
“Strong authentication should always be used when critical corporate and customer data needs protection against unauthorised access,” explained Marcus Ross, general manager in Germany of security specialists VeriSign. Ross counts among the typical areas of use as mobile access to corporate data via a VPN (Virtual Private Network) or hotspots and the network/Windows logon and protection for web applications.
Strong authentication can be applied in different ways. While the first factor – “knowledge” – is invariably a static password or a PIN code, companies have various options when it comes to applying the second principle. Namely: the “one-time password” (OTP) and digital certificates. These can be saved either to small hardware devices, called “tokens”, or directly to the user's desktop.
Authentication using one-time passwords
The one-time password is usually stored on a security token with a small display. After entering the PIN (knowledge), a numeric code generated by the token and valid for a short time – i.e. 20 seconds – appears. When logging onto the system, users first enter their username as usual and then the numeric code generated by the token. A special authentication server checks the numeric code and grants the user access to the system if it matches. Once the time limit has expired, the numeric code is no longer valid and therefore useless to any eavesdroppers.
“The strong authentication model is especially suitable for heterogeneous user landscapes, as installations on the client's corporate networks to allow access are not needed,” explained security expert Ross. It follows that an authentication system based on one-time passwords is also comparatively easy to implement – while at the same time offering considerably better security compared to username and static password. Companies who opt for this model, however, should compare prices from different suppliers, as these can vary considerably.
Authentication with digital certificates
Even more secure than one-time passwords is authentication via digital X.509 certificates. They function like a digital ID card and give users an certified internet identity. Personal digital certificates confirm the user's identity and prove the integrity of the data being sent via internet. The certificates are issued after careful scrutiny of identity by an independent certification authority such as VeriSign or RSA. Besides data about the person, a digital certificate contains what is called a public key. A second, secret key is only known to the owner and is stored by the certification authority.
The digital certificates, together with the identity data and public key, are stored on a USB-compatible token or a conventional smart card for use as part of strong authentication. When users try to log on to the corporate network, they connect their token with the USB slot or their smart card with the card reader. Instead of a password, the digital certificate and public key are sent to the authentication authority via internet. To ensure that the public key sent actually belongs to the person attempting to log on to the corporate networks, the independent certification authority confirms that the public key matches the secret key it has stored.
“Digital certificates as a variation on strong authentication are especially secure, and are winning more and more recognition in the security-conscious business world of banks and financial service providers,” said Ross. A study produced in November 2004 by Aladdin Knowledge Systems confirms the international trend to protect IT networks using these certificate-based solutions. Of the more than 350 security and IT managers surveyed in the financial services, government agencies, healthcare and telecommunications sectors, more than half of companies had already adapted their infrastructure correspondingly and had implemented or were planning in the near future to implement a certificate-issuing authority (CA).
PKI – more than the basis for personal digital certificates
The drawback of this solution is the higher cost of implementation compared to one-time passwords. That's because a PKI (Public Key Infrastructure) must be set up to generate the digital certificates. But as the Aladdin study shows, the investment quickly pays off: On the one hand, authentication using digital certificates offers a very high degree of security, and on the other hand, the PKI is not only the basis for digital certificates, but also plays a central role in the security infrastructure of all companies. The PKI then provides the basis for secure and trustworthy processing of all transactions via internet, also allowing other services such as the digital signature, data encryption, issuance of digital certificates for (web) servers and time stamping.
Tokens for all cases
The security industry has recognised that the simple handling of strong authentication by users represents a significant reason for their acceptance and continued success on the market. While the smart card has so far been unable to assert itself as a carrier of digital certificates everywhere, the USB-compatible tokens are becoming increasingly popular. They can simply be hooked up by the computer's USB port and do not require an extra card reader. The “all-in-one” token has been around for some time already. The VeriSign Multipurpose Next-Generation Token was one of the first on the market. It offers both the option of one-times passwords and PKI authentication, and can also save information on a smart card. It means that if a user doesn't have a USB port or card reader to hand, the one-time password can always be used for authentication. Similar products are available from RSA, Aladdin and others. And developments are stopping there: VeriSign and smart card specialists Gemplus only recently presented a solution which enables strong authentication directly via the digital certificates stored on the SIM card. It means that transactions in the future will be made securely and conveniently via mobile end devices such as mobile phones and PDAs.
Managing strong authentication intelligently
But the success or failure of a strong authentication systems does not only rest on user-friendliness. Important elements are also simple implementation and administration. To keep time needs and costs as low as possible, VeriSign has developed the Unified Authentication Platform. This solution enables companies to develop and manage the different types of strong authentication on a single platform. Its special advantage is that companies don't have to settle for one model in advance. They can start with a one-time password solution and later switch to digital certificates in connection with tokens or smart cards. What's more, existing directory services such as Microsoft Active Directory, Radius, servers or single-sign-on structures can be integrated into the system and reused. It allows system administrators to manage tokens and certificates in a familiar environment. Ross: “At last companies can adapt solutions for strong authentication to their infrastructure and budget – and not the other way round.” “Because we need strong authentication if we want to avoid squandering the hard-earned confidence in e-business.”
See also "Stronger is Better"
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