Baltimore Technologies: UniCERT 3.0 Certificate Authority System

by Paul Grosse - May 1999

Introduction

Companies that fail to take advantage of the low cost and ubiquitous nature of the Internet are destined to see their competitors leave them behind as opportunities for new and more secure business manifest themselves. With an Internet presence, from anywhere in the world and at any time of day, a company can advertise its products or do business, either with consumers or other businesses. However, making sure that the people or organisations with whom a company does business with are just who they say they are without some form of standardised infrastructure would be impossible.

In any ordinary exchange, both parties are able to authenticate each other, agree on terms and exchange monies for goods or services. However, on the Internet, trade can occur between parties anywhere on the planet so some form of mutual trust and authentication must exist in order to make this work.

Public Key Cryptography provides the basis upon which certified information may be exchanged securely between two parties and Certificate Authorities provide a trusted third party that can vouch for the validity of the credentials of both parties in any transaction - revoking any certificates as required. Such a system is called a Public Key Infrastructure (PKI).

Products

UniCERT

UniCERT provides digital certificate management services and enables full-strength authentication, integrity and confidentiality for: E-commerce; Secure E-mail; Internet Shopping; Secure Web Banking; Online Trading; and, Virtual Private Networks. It is based upon open standards of which the most important is X.509 version 3.0 thus allowing it to work with other CAs and systems that use X.509 certificates.

UniCERT's architecture is designed to be modular with components defined in key areas of functionality. At the top of the tree type structure, the Certificate Authority (CA) is central to the viability of the system, responsible for generating, publishing and revoking digital certificates. The CA is managed by the CA Operator (CAO) and beneath the CA are Registration Authorities (RAs) which act as the interface between the end user and the CA, carrying the burden of enrolment and acting as intermediary for authentication. In turn, the RAs are managed by RA Operators (RAOs). Each CA, CAO, RA, and RAO has its own certificate so that each component of the PKI is able to identify itself with other components and communicate securely.

The CA is performs a number of functions:

• It receives signed PKIX (Extended Public Key Infrastructure) messages from the RA that request the creation or revocation of a certificate. Upon receipt, the CA checks the signature and makes sure that the RA has been authorised to request such a procedure according to the configuration and the PKI policy;
• It generates and signs certificates according to the information that it is given and the policy being used. Signing is done using RSA, DSA (Digital Signature Algorithm) or ECDSA algorithms with key length being specified. The CA's private key may be protected by a hardware based security module;
• It returns the newly generated certificate to the person who requested it and, if configured to do so, is able to publish certificates to an external directory service such as X.500 supporting DAP (Directory Access Protocol) and LDAP (Lightweight Directory Access Protocol - effectively DAP but without some of the less important functionality);
• The CA revokes certificates upon receipt of a revocation request by marking as revoked on its internal certificate list the certificate in question and then adding the information to the next Certificate Revocation List (CRL);
• It publishes Certificate Revocation Lists in the same way as it publishes the original digital certificate but, in addition, UniCERT may also be configured to publish revocation information to an OCSP (On-line Certificate Status Protocol) responder or server which is able to supply up-to-date information regarding the status of digital certificates;
• The CA maintains a database of digital certificates and CRLs using an Oracle database - this may be located on the same system as the CA modules or, if required, may be located on a separate system in the case of a distributed system;
• It maintains an audit log making use of the fact that all of the entities in the PKI have their own certificate and therefore any activity on the system may be traced;
• It may be configured so that it has separate key pairs for signing certificates, response messages to RAs, revocations messages and so on; and,
• It stores and distributes the configuration information and policies maintained by the CAOs, to the appropriate RAs and RAOs.

Just as a graphics accelerator card in a PC will speed up the display of the machine, a Hardware Security Module will accelerate cryptographic operations such as generation of key pairs, signing of keys, generation of pseudo random numbers and so on, and will allow specialised storage of keys such as the CA's Root Key.

The CAO module is responsible for: managing the PKI - making use of Baltimore's PKI editor - which is used to add or maintain the PKI components (CAs, CAOs, RA and RAOs); managing the security policies for face to face and remote registration using the Security Policy Editor; Certificate Administration; and monitoring the audit log. It is possible to set up the PKI such that more than one CAO has access to a particular CA (or RAO has access to a particular RA) and therefore different CAOs and RAOs can have different access rights (such as only being able to inspect the audit log) or, the capabilities of the CAOs and RAOs may be distributed therefore decreasing further the chance of fraud.

Like all entities on the system, each CAO and RAO has a certificate (usually stored on a hardware token such as a smart card) and each operation performed by a CAO or RAO is signed and logged.

The PKI Editor uses a graphical user interface that depicts the PKI as a tree structure with each component and the relationships between them easily identifiable. The PKI Editor allows the user to: edit certain elements of the CA module such as frequency of publication of CRLs and so on; delete, edit and add new CAOs and RAOs with the necessary generation of keys and certificates and definition of appropriate roles and policies; addition and deletion of RAs; generation of sub CAs, certifying public keys; and, Cross certifying the CA's public key with other CA's public keys using PKIX, PKCS 10 and certificate based cross certification along with confirmation of MD5 hash.

The Security Policy Editor is used by the CAO to; configure and lay out the registration screens and digital certificate templates that are used by RAOs when authenticating a certificate request; define the extensions that are to be included in the digital certificate (full extension support is given to PKIX and X.509 v3.0 standards and, in addition, the operator is able to add custom extensions); specify whether keys are to be generated by the RAO or that the public key is to be supplied by the user; define the period of validity of the certificate; the number of keys and uses of each key; key details such as algorithm to be used and key length; if the key may be renewed automatically and if so, how; and how many RAOs are required to authenticate a request.

The Security Policy Editor is sufficiently flexible for field labels to be defined in any language, have default values - again, in any language - specify whether or not any particular field is editable by the operator and whether or not a field is mandatory.

The UniCERT RA acts as an intermediary passing certification requests from the RAOs, and the RA Gateway (from web browsers, e-mail, VPNs and so on) to the CA. In addition it also: manages revocation requests from RAOs (sent to the CA as a signed PKIX revocation request); maintains a database of all transactions using Oracle; and, maintains an audit log. Should communications between the RA and CA fail, transactions are queued at the RA until such times as they can be established again.

In addition to the above, there is also an optional Key Archive Module that is used for archiving the end entity private keys that are used for encryption. Only the encryption keys are archived leaving the signing private key alone - if the signing key pair was also archived, any argument for non-repudiation would disappear.

Platforms

For a small CA, UniCERT may be operated on a single Microsoft Windows NT platform although any component may be moved to a separate PC within a distributed system.

Oracle:

• Any Oracle supported platform - UniCERT supports Oracle 8 in addition to Oracle 7

UniCERT - CA:

• Microsoft Windows NT 4.0 Server
• 200 MHz Pentium recommended
• 1 Gb Hard Disc space recommended
• 64 Mb RAM recommended

UniCERT - CA Operator:

• Microsoft Windows NT 4.0 Workstation
• 166 MHz Pentium
• 64 Mb RAM

UniCERT - RA:

• Microsoft Windows NT 4.0 Server
• 200 MHz Pentium
• 1 Gb Hard Disc space recommended
• 64 Mb RAM

UniCERT - RA Operator:

• Microsoft Windows NT 4.0 Workstation or Microsoft Windows 95
• 166 MHz Pentium
• 64 Mb RAM

UniCERT - RA Gateway:

• Microsoft Windows NT 4.0
• 166 MHz Pentium
• 64 Mb RAM

Smart Card Readers and Cards:

• Datakey; and,
• Gemplus.

Hardware Security Modules supported:

• Baltimore's HSP4000 - Assure;
• RACAL RG722; and,
• Chrysalis Luna2 and Luna CA
  

Pricing

UniCERT $5,000

Opinion

As the Internet grows exponentially and e-commerce along with e-business takes a hold, companies that fail to get involved sufficiently early will always remain behind those that did. One of the biggest problems however, is choosing which product to go for. Standards play an important role in any choice of product as does ease of use - UniCERT having both of these.

Open standards such as those for X.509 3.0 certificates as specified in ITU RFC 1422 are important as they are open to peer review so apart from being more carefully written in the first place, any bugs that are there are plain for anyone to see and fixes can be issued quickly - something that is not present in specifications that are kept secret. With Public Key Cryptography, knowing the algorithm as well as knowing the output of a message does not give away the key. With this in mind, peer review is a strength and not a weakness.

In addition to X.509 3.0, UniCERT supports DSA and ECDSA signing algorithms, PKIX messages, PKCS standards 1, 5, 7, 8, 9, 10, 11 and 12 along with DAP and LDAP and the use of generic SQL database management operations. Without any peculiar pieces of software lurking around the system, the modules should all work together as designed

Any Certificate authority depends upon the integrity of the root key - the private key that is used to validate all other certificates. This should be sufficiently long so that a brute force attack (trying every key in turn until the correct key is found) is computationally unfeasible. Not that long ago, Blaze, Diffie, Rivest, Schneier, Shimimora, Thompson and Wiener reported on the minimum key lengths for symmetric cyphers to provide adequate commercial security, stating that an organisation with the resources of the NSA would take 200 microseconds to break a 40 bit key and 12 seconds to break a 56 bit key. Adding one bit to the key length doubles the time taken to break the key using brute force and it was recommended that for 20 years protection, a key length of 90 bits should be used by CAs to prevent the back engineering of time dependent documents such as wills and so on. The long keys used by CAs are safe enough to guard against brute force attack as this method would require more computational power and time that could exist in the universe.

However, brute force is not the only method of attack. Recently SSL was shown to be vulnerable to an adaptive attack - RSA in SSL will give away information about an error so by tayloring a series of errors, sufficient information was given away regarding the key that the session was compromised. An additional tool to the hacker's armoury is social engineering whereby information or even physical tokens may be obtained for later use and if done cleverly, the victim may never suspect a thing - a return to work from a holiday may reveal some interesting information about someone that they thought they knew.

Concerns regarding key length and social engineering are really things to be considered and are not faults of any particular CA system. However, putting a great deal of importance on a single piece of information can make a computer system, the buildings that house the system, the site and the people who work on that site (full time or even the cleaner) vulnerable to attack and steps must be taken by management to ensure that they become suspicious of any behaviour that is directed at them regarding the security of either themselves or of the site.

Strengths

• Open standards make for a more secure system as the purchasers of such a system know that they are not getting something that has not been thoroughly tested first. UniCERT 3.0 has been accepted for evaluation to ITSEC/E3.
• A Visual interface for the PKI structure makes everything easier to comprehend as the relationships between the various components of the PKI can be seen directly. Simply Dragging and dropping PKI components onto the screen greatly simplifies the process that under any other circumstances would mean trying to interpret lines of what looks like program code or trying to visualise information on endless forms.
• The hardware security modules for key storage and cryptographic functionality greatly speed up the cryptographic processing of the system as this is all done by a component that is meant to do only that job. In addition, the secure storage of the keys is of paramount importance and should not be left in a place that could, in the event of a network breach, become vulnerable such as in a file on a hard drive.

Weaknesses

• Remote enrolment always provides a risk and it should be realised that any certification that requires only a low level of proof of identity cannot provide a higher level below it. The saying goes 'on the Internet, nobody knows you're a dog' and remote certification without proper identification can lead to enrolment fraud.
• The physical security of the building in which the root key is stored and any other places it is stored as a backup need to be assessed carefully. A great deal of attention on just one place makes it an ideal target for hackers, whether it is through electronic or social engineering.
• The system runs on Windows NT which is a highly available operating system with many know flaws and patches. Like any program, setting it up incorrectly or making peculiar tweaks to its functionality can lead to it malfunctioning through no fault of the vendor. Running programs on the machine that are not intended to run alongside the CA could (through the fault of neither) cause the system to be compromised. A CA running on a machine should only have the CA running on it.

Conclusions

Companies cannot afford to let the opportunities of e-commerce and e-business pass them by and with a number of different systems available the choice becomes dependent upon criteria such as: Are open standards used?; is it comprehensive enough to fulfil the other requirements of PKI such as secure mail, web access and so on?; is it truly global?; and, Is it easy enough to configure and use? Baltimore Technologies appear to have succeeded in all of these and, as their customer list shows, they have attracted some important clients around the world.

Being based in Ireland, the company does not face the same set of restrictions when considering expanding into a global market as the US companies do, making it even more attractive to potential purchasers of UniCERT and other products.

Company Profile

Baltimore is the operating name of Zergo Holdings plc (London: ZGO) which acquired Security Domain in March 1998 and Baltimore Technologies in January 1999. Baltimore started off in Dublin in 1976 as a privately held company and Zergo was founded in 1988, going public on the LSE in July 1998. As a result of Zergo's acquisition of Balitmore, the resulting company has shown a substantial increase in size with the figures for 31st December 1997 and 31st December 1998 for: the number of employees rising from 120 to 337; Market Capitalisation from £20m to £117m; and, the number of offices world-wide increasing from 3 to 11. Compared to the Baltimore Technologies of two years ago, the company has launched a new line of security products and grown its revenues by over one hundred fold. Baltimore now has offices in the UK, Ireland, The Netherlands, Singapore, Hong Kong, Japan, USA and Australia.

The company's product portfolio is centred around cryptographic security products to support the secure movement of sensitive data and money around the world, covering financial institutions, governments and commercial enterprises. The company has opted for international security standards and APIs combined with a modular approach based upon open systems allowing its products to integrate with existing systems - software tool-kits providing allowing software developers to build strong security into existing applications.

Baltimore Technologies' Public Key Infrastructure product is UniCERT. For e-commerce and web browsers, MailSecure (an S/MIME-compatible e-mail plug-in for Microsoft Exchange), WebSecure (Secure Web browsing and Java communications system) and Forms (end-to-end security for Web based e-commerce applications which precludes frames based forms attacks). For developers, there is: PKI-plus (to PKI-enable any application); Crypto systems tool-kit; Secure messaging tool-kit; C/SSL; Secure platforms; and, for Java Security there is J/SSL and J/Crypto. The company also supplies Assure, a cryptographic API and high-performance, tamperproof, cryptographic coprocessor or PCs. In addition to all of this, Baltimore offers a consultancy along with education and training.

The company has an extensive partner scheme with Enterprise Solutions Partners: Com Tech Communications Pty Ltd; Deloitte & Touche - DTI; Global Business Solutions; and, KPMG TTP Services. The company also has a number of resellers which includes: ARTICON Information Systems AG; Brokat Informationssysteme GmbH; Centaur; Intercede; ISOCOR Switzerland; NetVisions nv; and, Platinum Technology AG; with PriceWaterhouseCoopers as a consulting partner.

Baltimore has clients in over 40 countries and they include: ABN-AMRO Bank; Australian Taxation Office; Bank of England; Bank of Ireland; BP International; BT; Bull Information Systems; Cable and Wireless plc; Citibank; Commerzbank - Frankfurt; Digital Equipment Corporation; Dow Jones Telerate; European Union; GEC Marconi Secure Systems; Hewlett-Packard; IBM; ICL; National Lottery; National Health Service; RACAL Telecom; RSA Data Security inc.; and, Visa International.

Recently, Baltimore Technologies helped make e-commerce history when its digital signature system was used by US President Bill Clinton and Ireland Prime Minister Bertie Ahern to execute the first digitally signed state document between governments. The company was also ISA Company of the year and was awarded the European IT Prize and Information Security Product of the Year 1998 for its UniCERT Certificate Authority system. The company was also named BMW Business of the Month and received the 1998 Irish National Innovation Award.

In the US:
Baltimore Technologies Inc.
101 East Park Boulevard
6th Floor
Plano
Texas 75074
USA
Tel: +1 972 516 3744
Fax: +1 972 516 3745

US offices also in:

• New York NY;
• Washington DC;
• Boston MA;
• Mountain View CA; and,
• San Mateo CA.

Email: info@baltimore.com
WWW: http://www.baltimore.com/

In the UK:
Baltimore Technology Ltd.
The Square
Basing View
Basingstoke
Hampshire RG21 4EG
Tel: +44 (0)1442 342600
Fax: +44 (0)1256 812901
Email: info@baltimore.com
WWW: http://www.baltimore.com/

Copyright (c) 1999 P. A. Grosse. All Rights Reserved.

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