INTERNET-DRAFT Stefan Santesson (3xA Security) Intended Status: Proposed Standard Russ Housley (Vigil Security) Updates: 3709 (once approved) Siddharth Bajaj (VeriSign) Expires: May 15, 2010 Leonard Rosenthol (Adobe) November 11, 2009 Internet X.509 Public Key Infrastructure - Certificate Image Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html Copyright and License Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the BSD License. Santesson et all. Expires May 15, 2010 [Page 1] INTERNET DRAFT Certificate Image November 11, 2009 Abstract This document specifies a method to bind a visual representation of a certificate in the form of a certificate image to a [RFC5280] public key certificate by defining a new otherLogos image type according to [RFC3709]. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2 Terminology . . . . . . . . . . . . . . . . . . . . . . . . 4 2 Certificate Image . . . . . . . . . . . . . . . . . . . . . . . 5 3 LogotypeImageInfo . . . . . . . . . . . . . . . . . . . . . . . . 5 4 Certificate Image Formats . . . . . . . . . . . . . . . . . . . 6 4.1 PDF . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.2 SVG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 4.2 PNG . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5 Embedded images . . . . . . . . . . . . . . . . . . . . . . . . 7 6 Security Considerations . . . . . . . . . . . . . . . . . . . . 9 7 IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 9 8 References . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 8.1 Normative References . . . . . . . . . . . . . . . . . . . . 9 8.2 Informative References . . . . . . . . . . . . . . . . . . 10 Appendix A - data: URI example . . . . . . . . . . . . . . . . . 11 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 Santesson et all. Expires May 15, 2010 [Page 2] INTERNET DRAFT Certificate Image November 11, 2009 1. Introduction This standard specifies how to bind a Certificate Image, providing a visual representation of a certificate, to that [RFC5280] certificate using the Logotype extension defined in [RFC3709], specifying the Certificate Image as a new otherLogos type. The purpose of the Certificate image is to aid human interpretation of a certificate by providing meaningful visual information to the user interface. Typical situations when a human needs to examine the visual representation of a certificate are: - A person establishes secured channel with an authenticated service. The person needs to determine the identity of the service based on the authenticated credentials. - A person validates the signature on critical information, such as signed executable code, and needs to determine the identity of the signer based on the signer's certificate. - A person is required to select an appropriate certificate to be used when authenticating to a service or Identity Management infrastructure. The person needs to see the available certificates in order to distinguish between them in the selection process. Display of a certificate information to humans is challenging due to lack of well defined semantics for critical identity attributes. Unless the application has out of band knowledge about a particular certificate, the application will not know the exact nature of the data stored in common identification attributes such as serialNumber, organizationName, country, etc. Consequently the application can display the actual data, but faces problem to label that data in the UI, informing the human about the exact nature (semantics) of that data. It is also challenging for the application to determine which identification attribute that are important to display and how to organize them in a logical order. RFC 3709 [RFC3709] defines a certificate extension for binding images to a certificate, such as community logo and issuer logo, enhancing display of certificate information. The syntax is extensible and allows inclusion of new image types using the other-Logos structure. This standard defines how to include a complete certificate image using the extensibility mechanism of RFC 3709. Santesson et all. Expires May 15, 2010 [Page 3] INTERNET DRAFT Certificate Image November 11, 2009 1.2 Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. Santesson et all. Expires May 15, 2010 [Page 4] INTERNET DRAFT Certificate Image November 11, 2009 2 Certificate Image This section defines the Certificate Image as a new otherLogos type according to section 4.1 of [RFC3709]. The Certificate Image otherLogos type is identified by the Object Identifier (OID) id-logo-certimage. id-pkix OBJECT IDENTIFIER ::= { iso(1) identified-organization(3) dod(6) internet(1) security(5) mechanisms(5) pkix(7) } id-logo OBJECT IDENTIFIER ::= { id-pkix 20 } id-logo-certimage OBJECT IDENTIFIER ::= { id-logo TBD } //* Note: TBD is to be replaced by a real OID before publication of this draft *// When present the Certificate Image MUST represent a complete visual representation of the certificate. This means that the display of this certificate image represents all information about the certificate that the issuer subjectively defines as relevant to show a typical human user within the typical intended use of the certificate, giving adequate information about at least the following three aspects of the certificate: - Certificate Context - Certificate Issuer - Certificate Subject Certificate Context information is visual marks and/or textual information which helps the typical user to understand the typical usage and/or purpose of the certificate It is up to the issuer to decide what information in the form of text and graphical symbols and elements, which represents a complete visual representation of the certificate. Applications providing a Graphical User Interface (GUI) to the certificate user MAY present a Certificate Image according to this standard in any given application interface, as the only visual representation of a certificate. 3 LogotypeImageInfo The optional LogotypeImageInfo structure is defined in [RFC3709] and is included here for convenience: Santesson et all. Expires May 15, 2010 [Page 5] INTERNET DRAFT Certificate Image November 11, 2009 LogotypeImageInfo ::= SEQUENCE { type [0] LogotypeImageType DEFAULT color, fileSize INTEGER, -- In octets xSize INTEGER, -- Horizontal size in pixels ySize INTEGER, -- Vertical size in pixels resolution LogotypeImageResolution OPTIONAL, language [4] IA5String OPTIONAL } -- RFC 3066 Language Tag When the optional LogotypeImageInfo is included with a certificate image, the parameters shall be used with the following semantics and restrictions. xSize and ySize represents recommended display size for the image. When a value of 0 (zero) is present, no recommended display size specified. When non-zero values are present and these values differ from corresponding size values in the referenced image file, then the referenced image SHOULD be scaled to fit within the size parameters of LogotypeImageInfo, while keeping x and y ratio intact. Resolution MUST NOT be specified. 4 Certificate Image Formats 4.1 PDF A Certificate Image MAY be provided in the form of a Portable Document Format (PDF) document according to [ISO32000] following the conventions defined in this section. When a certificate image is formatted as a PDF document, it MUST also be formatted according to the profile PDF/A [ISO19005]. When including a PDF document as Certificate Image, the following MIME media type as specified in [RFC3778] MUST be used as mediaType in LogotypeDetails: application/pdf 4.2 SVG A Certificate Image MAY be provided in the form of a Scalable Vector Graphic (SVG) image, which MUST follow the SVG Tiny profile [SVGT1.2] The following MIME media type defined in Appendix M of [SVGT1.2] MUST be used as mediaType in LogotypeDetails for SVG images: image/svg+xml Santesson et all. Expires May 15, 2010 [Page 6] INTERNET DRAFT Certificate Image November 11, 2009 The SVG image file MUST NOT incorporate any external image data by reference to an external SVG document, or by reference to an external media source other than SVG. Doing so would incorporate image data that is not covered by the logotypeHash value of the image. Certificate using applications MUST reject any image that violates this rule. The XML structure in the SVG file MUST use (linefeed 0x0A) as end-of-line (EOL) character when calculating the hash over the SVG file. The referenced SVG file may be provided in compressed form, for example as SVG.GZ or SVGZ. It is outside the scope of this specification to specify any such compression algorithm. However, after decompression the EOL characters of the SVG file MUST be normalized according to this section before computing the hash of the SVG file. 4.2 PNG If a certificate image is provided as a bit mapped image, the PNG [ISO15948] format SHOULD be used. PNG images are identified by the following mediaType in LogotypeDetails: image/png 5 Embedded images The certificate image otherLogos type MAY be stored within the logotype extension using the "data" URL scheme defined in RFC 2397 [RFC2397] if the logotype image is provided through direct addressing, i.e. the image is referenced using the LogotypeDetails structure. The syntax of Logotype details defined in RFC 3709 is included here for convenience: LogotypeDetails ::= SEQUENCE { mediaType IA5String, -- MIME media type name and optional -- parameters logotypeHash SEQUENCE SIZE (1..MAX) OF HashAlgAndValue, logotypeURI SEQUENCE SIZE (1..MAX) OF IA5String } Santesson et all. Expires May 15, 2010 [Page 7] INTERNET DRAFT Certificate Image November 11, 2009 When including the image data in the logotype extension using the "data" URL scheme the following conventions apply. - the value of mediaType MUST be identical to the mediatype value in the "data:" URL. - The hash of the image MUST be included in logotypeHash and MUST be calculated over the same data as it would have been, had the image been referenced through a link to an external resource. Note: As the "data:" URL scheme is processed as a data source rather than as a URL, the image data is typically not limited by any URL length limit setting that otherwise apply to URLs in general. Note: Implementations need to be cautious about the the size of images included in a certificate in order to ensure that the size of the certificate does not prevent the certificate to be used as intended. Santesson et all. Expires May 15, 2010 [Page 8] INTERNET DRAFT Certificate Image November 11, 2009 6 Security Considerations The security considerations of [RFC3709] apply also to this standard. This standard makes it possible for a CA to issue a certificate with a Certificate Image that is in conflict with other data included in the certificate without the relying party application being able to detect the delta. A relying party application MUST decide that the certificate is valid and trustworthy enough to provide a Certificate Image before using it. Referenced image files are hashed in order to bind the image to the signature of the certificate. Some image types, such as SVG allow part of the image to be collected from external source by incorporating a reference to an external image file. If this feature were used within a certificate image file, the hash of the image file would only cover the URI reference to the external image file, but not the referenced image data. To ensure that the hash of the certificate image covers the whole image, implementations of this standard MUST reject images that incorporate parts of the image by reference to external image files. CAs issuing certificate with embedded certificate images should be cautious when accepting graphics from the certificate requestor for inclusion in the certificate if the hash algorithm used to sign the certificate is vulnerable to collision attacks. In such case the accepted image may contain data that could help an attacker to obtain colliding certificates with identical certificate signatures. 7 IANA Considerations This document requires no actions from IANA. 8 References 8.1 Normative References [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 [RFC5280] Cooper, D., Santesson, S., Farrell, S., Boeyen, S., Housley, R., and W. Polk, "Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile", RFC 5280, May 2008 Santesson et all. Expires May 15, 2010 [Page 9] INTERNET DRAFT Certificate Image November 11, 2009 [RFC3709] S. Santesson, R. Housley, T. Freeman, "Internet X.509 Public Key Infrastructure Logotypes in X.509 Certificates", RFC 3709, February 2004 [RFC2397] L. Masinter, 'The "data" URL scheme' RFC 2397, August 1998 [ISO32000] ISO 32000-1:2008, "Document management - Portable document format" -- Part 1: PDF 1.7, April 2008 [ISO19005] ISO 19005-1:2005, "Document Management - Electronic document file format for long term preservation - Part 1: Use of PDF 1.4 (PDF/A-1)", 2005 [ISO15948] ISO/IEC 15948:2004, "Information technology - Computer graphics and image processing -- Portable Network Graphics (PNG): Functional specification", 2004 [SVGT1.2] W3C Recommendation, "Scalable Vector Graphics (SVG) Tiny 1.2 Specification", December 2008 8.2 Informative References [RFC3778] E. Taft, J. Pravetz, S. Zilles, L. Masinter "The application/pdf Media Type", RFC 3778, May 2004 Santesson et all. Expires May 15, 2010 [Page 10] INTERNET DRAFT Certificate Image November 11, 2009 Appendix A - data: URI example The following example stores an embedded SVG image using the data: URI scheme. data:image/svg+xml;base64, PD94bWwgdmVyc2lvbj0iMS4wIiBlbmNvZGluZz0iVVRGLTgiIHN0YW5kYWxvbmU9 Im5vIj8+DQo8IS0tIENyZWF0ZWQgd2l0aCBJbmtzY2FwZSAoaHR0cDovL3d3dy5p bmtzY2FwZS5vcmcvKSAtLT4NCjxzdmcNCiAgIHhtbG5zOmRjPSJodHRwOi8vcHVy bC5vcmcvZGMvZWxlbWVudHMvMS4xLyINCiAgIHhtbG5zOmNjPSJodHRwOi8vY3Jl YXRpdmVjb21tb25zLm9yZy9ucyMiDQogICB4bWxuczpyZGY9Imh0dHA6Ly93d3cu dzMub3JnLzE5OTkvMDIvMjItcmRmLXN5bnRheC1ucyMiDQogICB4bWxuczpzdmc9 Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIg0KICAgeG1sbnM9Imh0dHA6Ly93 d3cudzMub3JnLzIwMDAvc3ZnIg0KICAgeG1sbnM6eGxpbms9Imh0dHA6Ly93d3cu dzMub3JnLzE5OTkveGxpbmsiDQogICB4bWxuczpzb2RpcG9kaT0iaHR0cDovL3Nv ZGlwb2RpLnNvdXJjZWZvcmdlLm5ldC9EVEQvc29kaXBvZGktMC5kdGQiDQogICB4 bWxuczppbmtzY2FwZT0iaHR0cDovL3d3dy5pbmtzY2FwZS5vcmcvbmFtZXNwYWNl cy9pbmtzY2FwZSINCiAgIGlkPSJzdmczNTUyIg0KICAgc29kaXBvZGk6dmVyc2lv bj0iMC4zMiINCiAgIGlua3NjYXBlOnZlcnNpb249IjAuNDYiDQogICB3aWR0aD0i NDAxIg0KICAgaGVpZ2h0PSI0MDEiDQogICB2ZXJzaW9uPSIxLjAiDQogICBzb2Rp cG9kaTpkb2NuYW1lPSJ0aWNrZXRmcmFtZS5zdmciDQogICBpbmtzY2FwZTpvdXRw dXRfZXh0ZW5zaW9uPSJvcmcuaW5rc2NhcGUub3V0cHV0LnN2Zy5pbmtzY2FwZSI+ DQogIDxtZXRhZGF0YQ0KICAgICBpZD0ibWV0YWRhdGEzNTU3Ij4NCiAgICA8cmRm OlJERj4NCiAgICAgIDxjYzpXb3JrDQogICAgICAgICByZGY6YWJvdXQ9IiI+DQog ICAgICAgIDxkYzpmb3JtYXQ+aW1hZ2Uvc3ZnK3htbDwvZGM6Zm9ybWF0Pg0KICAg ICAgICA8ZGM6dHlwZQ0KICAgICAgICAgICByZGY6cmVzb3VyY2U9Imh0dHA6Ly9w dXJsLm9yZy9kYy9kY21pdHlwZS9TdGlsbEltYWdlIiAvPg0KICAgICAgPC9jYzpX b3JrPg0KICAgIDwvcmRmOlJERj4NCiAgPC9tZXRhZGF0YT4NCiAgPGRlZnMNCiAg ICAgaWQ9ImRlZnMzNTU1Ij4NCiAgICA8aW5rc2NhcGU6cGVyc3BlY3RpdmUNCiAg ICAgICBzb2RpcG9kaTp0eXBlPSJpbmtzY2FwZTpwZXJzcDNkIg0KICAgICAgIGlu a3NjYXBlOnZwX3g9IjAgOiA1MjYuMTgxMDkgOiAxIg0KICAgICAgIGlua3NjYXBl OnZwX3k9IjAgOiAxMDAwIDogMCINCiAgICAgICBpbmtzY2FwZTp2cF96PSI3NDQu MDk0NDggOiA1MjYuMTgxMDkgOiAxIg0KICAgICAgIGlua3NjYXBlOnBlcnNwM2Qt b3JpZ2luPSIzNzIuMDQ3MjQgOiAzNTAuNzg3MzkgOiAxIg0KICAgICAgIGlkPSJw ZXJzcGVjdGl2ZTM1NTkiIC8+DQogIDwvZGVmcz4NCiAgPHNvZGlwb2RpOm5hbWVk dmlldw0KICAgICBpbmtzY2FwZTp3aW5kb3ctaGVpZ2h0PSI3MzkiDQogICAgIGlu a3NjYXBlOndpbmRvdy13aWR0aD0iMTI4MCINCiAgICAgaW5rc2NhcGU6cGFnZXNo YWRvdz0iMiINCiAgICAgaW5rc2NhcGU6cGFnZW9wYWNpdHk9IjAuMCINCiAgICAg Z3VpZGV0b2xlcmFuY2U9IjEwLjAiDQogICAgIGdyaWR0b2xlcmFuY2U9IjEwLjAi DQogICAgIG9iamVjdHRvbGVyYW5jZT0iMTAuMCINCiAgICAgYm9yZGVyb3BhY2l0 eT0iMS4wIg0KICAgICBib3JkZXJjb2xvcj0iIzY2NjY2NiINCiAgICAgcGFnZWNv bG9yPSIjZmZmZmZmIg0KICAgICBpZD0iYmFzZSINCiAgICAgc2hvd2dyaWQ9ImZh bHNlIg0KICAgICBpbmtzY2FwZTp6b29tPSIxLjE1MjExOTciDQogICAgIGlua3Nj YXBlOmN4PSIyMDAuNSINCiAgICAgaW5rc2NhcGU6Y3k9IjIwMC41Ig0KICAgICBp bmtzY2FwZTp3aW5kb3cteD0iLTkiDQogICAgIGlua3NjYXBlOndpbmRvdy15PSIt OSINCiAgICAgaW5rc2NhcGU6Y3VycmVudC1sYXllcj0ic3ZnMzU1MiIgLz4NCiAg PHBhdGgNCiAgICAgc3R5bGU9ImZpbGw6IzAwMDAwMCINCiAgICAgZD0iTSAzOC40 NTczLDM5OC41IEMgMzguMjk4NzAxLDM5Ny45NSAzNy45MTcyMTEsMzk1LjA1Mzc2 Santesson et all. Expires May 15, 2010 [Page 11] INTERNET DRAFT Certificate Image November 11, 2009 IDM3LjYwOTU0NSwzOTIuMDYzOTEgQyAzNi4wOTA2NTcsMzc3LjMwMzYyIDI0LjI1 NjQ4LDM2NS45NjIxMiA2Ljk0MDA4NDgsMzYyLjY3MTI3IEwgMC45OTM5ODQyLDM2 MS41NDEyNiBMIDEuMjQ2OTkyMSwyMDAuMDI0ODMgTCAxLjUsMzguNTA4Mzk5IEwg Ny4yODQxMjQsMzcuNzg1ODk5IEMgMjQuMjM5MTU4LDM1LjY2ODAzMiAzNi4xODkx MTcsMjIuNjE5ODg1IDM4LjIyNjQ1Niw0IEwgMzguNSwxLjUgTCAyMDAuMjUsMS4y NDY5NzkyIEwgMzYyLDAuOTkzOTU4MzggTCAzNjIuMDEwODIsNC4yNDY5NzkyIEMg MzYyLjAyNDA3LDguMjI2NDQ5MiAzNjQuMTI4NzIsMTUuMzcxODMzIDM2Ni44NzA3 OSwyMC43NDY3MjkgQyAzNzEuMTk3NjcsMjkuMjI4MTEyIDM4Mi4xNzE5NywzNi4w MzM4MjIgMzk0LjM0NjY5LDM3Ljc4NTg5OSBMIDM5OS41LDM4LjUyNzUxOCBMIDM5 OS43NTMwMiwyMDAuMjYzNzYgTCA0MDAuMDA2MDQsMzYyIEwgMzk2Ljc1MzAyLDM2 Mi4wMTE4NyBDIDM5Mi42MTkwMSwzNjIuMDI2OTUgMzg0LjQ3NDI4LDM2NC4xODQz OSAzODAuMTk2ODIsMzY2LjM5NzQxIEMgMzcxLjk0MDE0LDM3MC42NjkxNCAzNjQu NzA1MzIsMzgxLjg4OTIyIDM2Mi44MDI1MywzOTMuMzczMjMgTCAzNjEuNzg3Mzks Mzk5LjUgTCAyMDAuMjY2NTMsMzk5LjUgQyA5My40NDQ4NTgsMzk5LjUgMzguNjQ4 MDA4LDM5OS4xNjEzNSAzOC40NTczLDM5OC41IHogTSAzNTQuOTMwNjEsMzgzLjk4 ODgxIEMgMzU5LjQ2NTMsMzY5LjMzMjUyIDM3MC4xNTYxNCwzNTguNTUwNDIgMzg0 LjEyNjYyLDM1NC41NDM1OCBMIDM4OS43NTMyNCwzNTIuOTI5ODIgTCAzODkuNjI2 NjIsMjAwLjIyMjU4IEwgMzg5LjUsNDcuNTE1MzQ3IEwgMzgzLjMxMzQ5LDQ1LjMx MDI5NSBDIDM3Ni44NjI2OSw0My4wMTEwNDQgMzcwLjE5MTM0LDM5LjI1NjI1MSAz NjYuMTA3NjcsMzUuNjI2NDQ0IEMgMzYyLjIxODI1LDMyLjE2OTMxMyAzNTYuMDU0 MTMsMjEuOTk0IDM1NC4zOTc5LDE2LjI5Njc4IEwgMzUyLjg1ODA4LDExIEwgMTk5 Ljk1Njk4LDExIEwgNDcuMDU1ODcsMTEgTCA0NS40ODA4ODQsMTYuNDE3NzYgQyA0 MS4zNTA0MiwzMC42MjYwNTcgMjcuNDIxOTY0LDQ0LjA4NzgxMyAxNC4yNSw0Ni42 MDIxOTMgTCAxMSw0Ny4yMjI1ODIgTCAxMSwyMDAuMzczNzggTCAxMSwzNTMuNTI0 OTggTCAxNy4yODE0NTYsMzU1LjMyMzkxIEMgMjkuNjMxMjA4LDM1OC44NjA3MiA0 MS4zNDI5NDQsMzcwLjE3NDk2IDQ1LjQxMjI5NywzODIuNSBDIDQ2LjMyMDI2NCwz ODUuMjUgNDcuMjYwMzY3LDM4OC4wNjM5NCA0Ny41MDE0MTUsMzg4Ljc1MzIgQyA0 Ny44NTA1NjYsMzg5Ljc1MTU3IDc4Ljk3ODIxNiwzODkuOTU0OTEgMjAwLjU4MjU2 LDM4OS43NTMyIEwgMzUzLjIyNTQ0LDM4OS41IEwgMzU0LjkzMDYxLDM4My45ODg4 MSB6Ig0KICAgICBpZD0icGF0aDM1NjMiIC8+DQo8L3N2Zz4NCg== Santesson et all. Expires May 15, 2010 [Page 12] INTERNET DRAFT Certificate Image November 11, 2009 The example above stores the following SVG image: image/svg+xml Santesson et all. Expires May 15, 2010 [Page 14] INTERNET DRAFT Certificate Image November 11, 2009 Authors' Addresses Stefan Santesson 3xA Security (AAA-sec.com) Bjornstorp 744 247 98 Genarp Sweden EMail: sts@aaa-sec.com Russell Housley Vigil Security, LLC 918 Spring Knoll Drive Herndon, VA 20170 USA EMail: housley@vigilsec.com Siddharth Bajaj VeriSign 685 East Middlefield rd Mountain view, CA 94043 USA Email: sbajaj@verisign.com Leonard Rosenthol 3533 Sunset Way Huntingdon Valley, PA 19006 USA Email: leonardr@adobe.com Santesson et all. Expires May 15, 2010 [Page 15]