Digital Signature Trust Company Selects ICL Directory as Secure PKI Repository.

RESTON, Va.--(BUSINESS WIRE)--Feb. 25, 1998--

Scalability and LDAP support meet large-scale needs of

commercial certification authority service

ICL today announced an agreement with Digital Signature Trust Company (DST), a premier provider of digital signature authentication and certification services to business and government, under which ICL will supply its i500 Enterprise Directory Server for DST's Certification Authority (CA) service.

Digital Signature Trust Company recently became the first financial institution to offer a third-party service to organizations implementing public key infrastructures (PKI). The ICL i500(R) directory is a global directory server that offers the speed and scalability large organizations require for LDAP and X.500 directories, along with simplified management and ease of use.

"After considerable evaluation, ICL's i500 directory was the only solution we found that could meet our current requirements for scalability and integration with a variety of PKI vendors," said Clay Epstein, DST chief technology officer.

"The directory will ultimately have to hold tens of millions of certificates while providing fast, easy and secure access for our customers. i500 provides that level of scalability, along with the high availability and support for the defacto LDAP standard we need. We also found its Information Gateway to be unique and especially useful for accessing external database information."

In a PKI environment, digital certificates are used in combination with public and private keys to certify the identity of the sender of electronic communications such as email and Web-based forms. The certificates are generated and managed by Certification Authorities. DST's repository offers the benefit of interoperability between corporate systems, allowing companies to extend transactions and data interchange beyond their own intranet into the enterprise of other organizations.

"The potential of electronic commerce will only be realized successfully when organizations can be sure their communications are secure and authenticated. DST has defined a new model for the industry as the first licensed Certification Authority and repository in the world. DST's service provides its customers with a reliable source for security that won't outgrow customer needs," said ICL's Director, i500 Americas Ed Harrington.

About i500 (www.i500directory.com)

ICL's i500 Enterprise Directory can support millions of entries on a single LDAP or X.500 server, and multiple servers can be interlinked for larger applications and unlimited scalability. Multiple searches can be performed in less than one second.

Add-on products provide simplified management and ease of use; these include the i500 Information Gateway, which enables directory client access to external databases, and iCon, a single-point directory configuration tool.

i500's Windows NT-based administration makes managing the directory easier and more intuitive than typical character-based administration tools.

i500 has been named to the prestigious Crossroads 98 A-List Awards sponsored by Open Systems Advisors. The A-List are the only industry awards based on interviews with customers who are actually deploying the products in mission-critical business situations.

About ICL

ICL Inc. is the U.S. software marketing arm of ICL PLC, a $4.5 billion global IT firm that supplies integrated systems and services. The company is the developer of DAIS(R), a CORBA-conformant Object Request Broker; the i500 Enterprise Directory Server and Dialogue Manager(tm), which provides desktop access to legacy databases.

ICL Inc. is headquartered at 11490 Commerce Park Drive, Reston, Virginia 20191, and can be reached by phone at [phone], by fax at [phone] or on the Web at http://www.iclinc.com.

About Digital Signature Trust Company

Digital Signature Trust Company (DST) is a subsidiary of Zions First National Bank, the largest subsidiary of Zions Bancorporation (Nasdaq: ZION). Under local management teams and community identities, Zions Bancorporation operates full-service banking offices in Arizona, California, Colorado, Idaho, Nevada, New Mexico and Utah. It also offers a comprehensive array of investment, mortgage, and insurance services and is a leader in providing innovative financing solutions for small businesses nationwide. Investor information can be accessed on the Internet at www.zionsbank.com.

DST is a premier provider of Secure Electronic Transaction (SET) and Public Key Infrastructure (PKI) technology services. DST issues, stores and verifies digital certificates, which are used in the digital "signing" of electronic documents and electronic transactions. DST provides secure certification services, including commercial Certification Authority (CA), service bureau CA and repository services, among others.

As the world's first licensed CA, DST issues digital certificates with technologies from CertCo, Entrust, GlobeSet, Netscape Communications (Nasdaq: NSCP) and Xcert based on the RSA set of algorithms (RSA Data Security Inc. is a subsidiary of Security Dynamics Technologies Inc.). DST also has the following strategic technology partners: Datakey, ICL, SAIC and Surety Technologies. For more information, call DST at 801-524-8673 or see its Web site at http://www.digsigtrust.com. -0-

ICL i500 and DAIS are registered trademarks and Dialogue Manager is a trademark of International Computers Limited in the USA, UK and other countries.

CONTACT: ICL Inc.

Anne Prine, [phone]

[e-mail]

http://www.iclinc.com

or

Mesa Communications

Audrey Bakke, [phone]

[e-mail]

or

Digital Signature Trust Co.

Jon Matonis, [phone]

[e-mail]

or

Politis Communications

Ken Jenson, [phone]

[e-mail]