Ristenpart Decl.
`
`UNITED STATES PATENT AND TRADEMARK OFFICE
`
`
`
`
`
`
`
`BEFORE THE PATENT TRIAL AND APPEAL BOARD
`_____________________
`
`Zoom Video Communications, Inc.,
`Petitioner,
`
`v.
`
`Cyph, Inc.,
`Patent Owner.
`______________________________________________________________
`
`Case No. IPR2023-00142
`
`U.S. Patent No. 9,794,070
`Issue Date: October 17, 2017
`
`
`
`
`DECLARATION OF DR. RISTENPART IN SUPPORT OF PETITION FOR
`INTER PARTES REVIEW OF
`U.S. PATENT NO. 9,794,070
`
`
`
`
`
`
`
`
`
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`
`
`TABLE OF CONTENTS
`
`Page
`
`INTRODUCTION ........................................................................................... 5
`I.
`QUALIFICATIONS ....................................................................................... 5
`II.
`III. MATERIALS CONSIDERED ........................................................................ 7
`IV. PERSON OF ORDINARY SKILL IN THE ART ........................................ 12
`V.
`LEGAL STANDARDS ................................................................................. 13
`A.
`Relevant Time Period for Invalidity Analysis .................................... 13
`B.
`Claim Construction ............................................................................. 13
`C.
`Anticipation ......................................................................................... 14
`D. Obviousness ........................................................................................ 14
`VI. SUMMARY OF OPINIONS ........................................................................ 17
`VII. TECHNOLOGY BACKGROUND .............................................................. 18
`A.
`Cryptography and Encryption ............................................................. 18
`B.
`Ephemeral Communication ................................................................ 21
`C. Web-Based Communications and Devices Used for Web-Based
`Communications ................................................................................. 23
`VIII. THE ’070 PATENT ...................................................................................... 31
`A.
`Specification ....................................................................................... 31
`B.
`Prosecution History ............................................................................. 38
`C.
`Challenged Claims .............................................................................. 39
`IX. OVERVIEW OF THE PRIOR ART ............................................................. 40
`A. Wauters (Ex. 1005) ............................................................................. 40
`B.
`Kaushik (Ex. 1006) ............................................................................. 43
`C.
`Gudjonsson (Ex. 1007) ....................................................................... 46
`X. GROUNDS ................................................................................................... 48
`
`
`
`1
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`A. Ground 1: Claims 1 and 2 Are Obvious Over Wauters in View of
`Gudjonsson ......................................................................................... 48
`1.
`Obviousness to a POSA ............................................................ 48
`a. Motivation to Combine .................................................. 48
`b.
`Reasonable Expectation of Success ............................... 52
`Claim 1 ..................................................................................... 54
`a.
`[1.0] “A method comprising:” ........................................ 54
`b.
`[1.1a] “sending a request, by a first user on a first device,
`to a server,” .................................................................... 54
`[1.1b] “the request comprising requesting the server open
`an ephemeral communication session with a second user
`on a second device;” ....................................................... 59
`[1.2] “allocating resources, by the server, to begin the
`ephemeral communication session between the first user
`and the second user;” ...................................................... 62
`[1.3a] “generating a unique ephemeral communication
`session identifier by the server for each ephemeral
`communication session and” .......................................... 66
`[1.3b] “transmitting the unique ephemeral
`communication session identifier to the first user;” ....... 69
`[1.4] “transmitting, by the first user, the unique
`ephemeral communication session identifier to the
`second user using a second communication channel;” .. 70
`[1.5] “connecting, by the second user, to the first user
`through the ephemeral communication session using the
`unique ephemeral communication session identifier;
`and;” ............................................................................... 71
`[1.6] “connecting, by the first user, to the second user
`through the ephemeral communication session using the
`unique ephemeral communication session identifier.” ... 73
`Claim 2 ..................................................................................... 73
`a.
`[2.0] “The method of claim 1, wherein:” ....................... 73
`b.
`[2.1] “connecting, by the second user, to the first user
`through the ephemeral communication session includes
`connecting to the server; and;” ....................................... 74
`
`c.
`
`d.
`
`e.
`
`f.
`
`g.
`
`h.
`
`i.
`
`
`
`
`
`2.
`
`3.
`
`2
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`c.
`
`c.
`
`d.
`
`e.
`
`f.
`
`g.
`
`h.
`
`i.
`
`[2.2] “connecting, by the first user, to the second user
`through the ephemeral communication session includes
`connecting to the server.” ............................................... 78
`Ground 2: Claims 1 and 2 Are Obvious Over Kaushik in View of
`Gudjonsson ......................................................................................... 78
`1.
`Obviousness to a POSA ............................................................ 78
`a. Motivation to Combine .................................................. 78
`b.
`Reasonable Expectation of Success ............................... 81
`Claim 1 ..................................................................................... 83
`a.
`[1.0] “A method comprising:” ........................................ 83
`b.
`[1.1a] “sending a request, by a first user on a first device,
`to a server,” .................................................................... 83
`[1.1b] “the request comprising requesting the server open
`an ephemeral communication session with a second user
`on a second device;” ....................................................... 86
`[1.2] “allocating resources, by the server, to begin the
`ephemeral communication session between the first user
`and the second user;” ...................................................... 89
`[1.3a] “generating a unique ephemeral communication
`session identifier by the server for each ephemeral
`communication session and” .......................................... 92
`[1.3b] “transmitting the unique ephemeral
`communication session identifier to the first user;” ....... 94
`[1.4] “transmitting, by the first user, the unique
`ephemeral communication session identifier to the
`second user using a second communication channel;” .. 95
`[1.5] “connecting, by the second user, to the first user
`through the ephemeral communication session using the
`unique ephemeral communication session identifier;
`and;” ............................................................................... 96
`[1.6] “connecting, by the first user, to the second user
`through the ephemeral communication session using the
`unique ephemeral communication session identifier.” ... 98
`Claim 2 ..................................................................................... 98
`a.
`[2.0] “The method of claim 1, wherein:” ....................... 98
`
`B.
`
`
`
`
`
`2.
`
`3.
`
`3
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`b.
`
`[2.1] “connecting, by the second user, to the first user
`through the ephemeral communication session includes
`connecting to the server; and;” ....................................... 98
`[2.2] “connecting, by the first user, to the second user
`through the ephemeral communication session includes
`connecting to the server.” ............................................. 101
`XI. NO SECONDARY CONSIDERATIONS .................................................. 101
`
`
`
`c.
`
`
`
`4
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`
`
`I.
`
`I, Thomas Ristenpart, Ph.D., declare as follows:
`
`INTRODUCTION
`1.
`I have been retained by counsel for Zoom Video Communications,
`
`Inc. (“Petitioner”) to provide my opinion regarding the validity of claims 1 and 2
`
`of U.S. Patent No. 9,794,070 (the “challenged claims” of the “’070 patent”)
`
`(attached as Ex. 1001 to the accompanying Petition for Inter Partes Review).
`
`2.
`
`I am being compensated at my standard rate of $400 per hour (plus
`
`expenses) for this matter. My payment is not contingent in any way on the
`
`outcome of this mater. I have no financial or other personal interest in the outcome
`
`of this matter.
`
`II. QUALIFICATIONS
`3.
`I have summarized in this section my educational background, career
`
`history, publications, and other relevant qualifications. My Curriculum Vitae,
`
`which includes my qualifications as well as my publications, is included as Ex.
`
`1004.
`
`4.
`
`I am an expert in the field of computer security, including applied and
`
`theoretical cryptography and privacy.
`
`5.
`
`I received a Bachelor of Science degree in Computer Science and
`
`Engineering from University of California, Davis in 2003. In 2005, I earned my
`
`Master of Science degree in Computer Science from University of California,
`
`
`
`5
`
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`
`Davis. And, in 2010, I earned a Ph.D. degree in Computer Science from
`
`University of California, San Diego. My doctoral studies focused on computer
`
`security and cryptography. My dissertation topic was on “New Approaches for
`
`Building Cryptographic Hash Functions”, which introduced new design methods
`
`for hash functions, a widely used cryptographic primitive.
`
`6. My work as an academic researcher has grown to touch on many areas
`
`of applied cryptography, with over one hundred peer-reviewed publications at the
`
`top academic venues in cryptography, security, and beyond. I have published in
`
`the area of encrypted messaging, for example my work on “Traceback for End-to-
`
`End Encrypted Messaging”; “Asymmetric Message Franking: Content Moderation
`
`for Metadata-Private End-to-End Encryption”; and “Orca: Blocklisting in Sender-
`
`Anonymous Messaging”. I served as co-program chair of the Advances in
`
`Cryptology—CRYPTO conference, a flagship publication venue conference of the
`
`International Association of Cryptologic Research (“IACR”). Being selected to be
`
`co-chair reflects the academic community’s high regard for my breadth and depth
`
`of expertise in cryptography. In addition to my academic work, I have experience
`
`working in industry to build cryptographic systems. I worked part time at
`
`Cloudflare to design and implement advanced cryptographic protocols that are now
`
`deployed for use in helping improve security in practice. Previously, I served on
`
`
`
`6
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`the cryptographic advisory board for Skyhigh Networks, which built cryptographic
`
`security products. My work has also led to many industry standards of wide use.
`
`III. MATERIALS CONSIDERED
`7.
`In forming the opinions set forth in this Declaration, I have considered
`
`and relied upon my education, research, experience, knowledge, and professional
`
`judgment, all documents cited in this Declaration, and the following documents,
`
`which I understand are being submitted as exhibits along with the Petition:
`
`Exhibit No. Description
`
`1001
`
`1002
`
`1005
`
`1006
`
`U.S. Patent No. 9,794,070 (“’070 patent”)
`
`File History for the ’070 patent (“’070 patent FH”)
`
`February 19, 2009 Snapshot of Robin Wauters, TinyChat Makes
`Creating Disposable Chat Rooms A Breeze, TechCrunch (Feb. 18,
`2009), archived at the Internet Archive’s Wayback Machine at
`https://web.archive.org/web/20090219092443/http://www.techcru
`nch.com/2009/02/18/tinychat-makes-creating-disposable-chat-
`rooms-a-breeze/ (“Wauters”)
`
`June 24, 2009 Snapshot of Kaushik, Create temporary and
`disposable chat rooms with Stinto, InstantFundas (Nov. 24, 2008),
`archived at the Internet Archive’s Wayback Machine at
`https://web.archive.org/web/20090624021641/http:/www.instantfu
`ndas.com/2008/11/create-temporary-and-disposable-chat.html
`(“Kaushik”)
`
`1007
`
`U.S. Patent No. 6,564,261 (“Gudjonsson”)
`
`1008
`
`Gustavus J. Simmons, Symmetric and Asymmetric Encryption,
`Vol. 11, No. 4 ACM Computing Surveys 305-330 (Dec. 1979),
`available at https://dl.acm.org/doi/10.1145/356789.356793
`
`
`
`7
`
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`
`
`
`
`Exhibit No. Description
`
`1009
`
`1010
`
`1011
`
`1012
`
`1013
`
`1014
`
`1015
`
`Jennifer Charteris, Sue Gregory, & Yvonne Masters, Snapchat
`‘selfies’: The case of disappearing data, Rhetoric and Reality:
`Critical perspectives on educational technology, Proceedings of
`ascilite Dunedin 2014, pp. 389-93, available at
`https://ascilite2014.otago.ac.nz/files/concisepapers/47-
`Charteris.pdf
`
`December 21, 2008 Snapshot of “Privacy Policy” webpage of the
`stinto.net website, archived at the Internet Archive’s Wayback
`Machine at
`https://web.archive.org/web/20081221154244/http://www.stinto.n
`et:80/datenschutz
`
`January 24, 2009 Snapshot of “About” webpage of the stinto.net
`website, archived at the Internet Archive’s Wayback Machine at
`http://web.archive.org/web/20090124112853/http://stinto.net:80/a
`bout
`
`Jason Fitzpatrick, Stinto Generates Disposable Chat Rooms,
`LifeHacker (Nov. 26, 2008), https://lifehacker.com/stinto-
`generates-disposable-chat-rooms-5099130
`
`Bright Hub, Review of Stinto – A Browser-Based Temporary Chat
`Room Application (Dec. 26, 2008),
`https://www.brighthub.com/environment/green-
`computing/articles/21594/
`
`Scott Gilbertson, TinyChat: Disposable, Web-Based Chat Anyone
`Can Use, Wired (Feb. 19, 2009), available at
`https://www.wired.com/2009/02/tinychat-dispos/
`
`June 27, 2013 Snapshot of azim, TinyChat: Online Chat Rooms
`Without Registering, MUO (Feb. 17, 2009), archived at the
`Internet Archive’s Wayback Machine at
`https://web.archive.org/web/20130627122802/https://www.makeu
`seof.com/tag/tinychat-create-free-chatroom/
`
`8
`
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`
`
`
`Exhibit No. Description
`
`1016
`
`1017
`
`1018
`
`1019
`
`1020
`
`1021
`
`1022
`
`February 21, 2009 Snapshot of Suganya, Chat With Your Friends
`Using TinyChat When Messengers Are Blocked At Your
`Office/School/University, Tech Dreams (February 20, 2009),
`archived at the Internet Archive’s Wayback Machine at
`https://web.archive.org/web/20090221191830/https://www.techdr
`eams.org/general/tinychat-%E2%80%93-an-unblocked-
`disposable-chat-even-at-your-office/1558-20090220
`
`December 18, 2014 Snapshot of “Help” webpage of the
`chattory.com website, archived at the Internet Archive’s Wayback
`Machine at
`http://web.archive.org/web/20141218122550/http://www.chattory.
`com/#
`
`Bazara I.A. Barry & Fatma M. Tom, Instant Messaging:
`Standards, Protocols, Applications, and Research Directions, in
`INTERNET POLICIES AND ISSUES, VOL. 7 1-15 (Chapter 8) (B.G.
`Kutais ed., Nova Science Publishers, Inc. 2010), available at
`https://www.researchgate.net/publication/280307922_Instant_Mes
`saging_Standards_Protocols_Applications_and_Research_Directio
`ns
`
`Tom Keating, Yahoo Messenger for the Web launches,
`TMCnet.com (May 2, 2007), https://blog.tmcnet.com/blog/tom-
`keating/news/yahoo-messenger-for-the-web-launches.asp
`
`Bogdan Popa, Yahoo Launches Web-Based Yahoo Messenger,
`Softpedia News (May 3, 2007),
`https://news.softpedia.com/news/Yahoo-Launches-Web-Based-
`Yahoo-Messenger-53796.shtml
`
`Adam Pash, Chat with AIM, MSN, Yahoo, and other contacts over
`Google Talk, LifeHacker (Aug. 14, 2007),
`https://lifehacker.com/chat-with-aim-msn-yahoo-and-other-
`contacts-over-goog-289097
`
`Peter Cohen, Flash-based ‘AIM Express’ debuts, Macworld (Aug.
`20, 2008),
`https://www.macworld.com/article/192065/aimexpress.html
`
`9
`
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`
`
`
`
`Exhibit No. Description
`
`Karl Gechlik, AIM Express lets you use IM without installing a
`client, MUO (June 21, 2008),
`https://www.makeuseof.com/tag/aim-express-lets-you-use-im-
`without-installing-a-client/
`
`AskVG.com, Windows Live Web Messenger: Web Based WLM,
`No Download or Installation Required (Oct. 15, 2009),
`https://www.askvg.com/windows-live-web-messenger-web-based-
`wlm-no-download-or-installation-required/
`
`April 3, 2013 Snapshot of tlk.io website, archived at the Internet
`Archive’s Wayback Machine at
`https://web.archive.org/web/20130403162621/http://tlk.io/
`
`August 1, 2014 Snapshot of tlk.io website, archived at the Internet
`Archive’s Wayback Machine at
`https://web.archive.org/web/20140801172659/http://tlk.io/
`
`November 23, 2014 Snapshot of Sagar Karira, Create Your Own
`Chat Room In Seconds With tlk.io, FossBytes (Nov. 11, 2014),
`archived at the Internet Archive’s Wayback Machine at
`https://web.archive.org/web/20141123102452/https://fossbytes.co
`m/chat-talk-discuss-online-without-hassle-tlk-io/
`
`Christian Dewes, Arne Wichmann, & Anja Feldmann, An analysis
`of Internet chat systems, IMC ’03, Proceedings of the 3rd ACM
`SIGCOMM Conference on Internet Measurement, pp. 51–64 (Oct.
`2003), available at https://dl.acm.org/doi/10.1145/948205.948214
`
`Michael Stephens, Tools from “Web 2.0 & Libraries: Best
`Practices for Social Software” Revisited, 5 Library Technology
`Reports 15-31 (Chapter 2) (Sept.-Oct. 2007), available at
`https://journals.ala.org/index.php/ltr/article/view/4822/5778
`
`U.S. Patent No. 7,562,116 (“Barsness”)
`
`U.S. Patent No. 7,912,903 (“Shah”)
`
`1023
`
`1024
`
`1025
`
`1026
`
`1027
`
`1028
`
`1029
`
`1030
`
`1031
`
`10
`
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`
`
`
`Exhibit No. Description
`
`1032
`
`1033
`
`1034
`
`1035
`
`1036
`
`1037
`
`1038
`
`1039
`
`1040
`
` J. Oikarinen & D. Reed, Network Working Group Request for
`Comments: 1459, Internet Relay Chat Protocol (May 1993),
`https://datatracker.ietf.org/doc/pdf/rfc1459
`
`Raymond B. Jennings III et al., A Study of Internet Instant
`Messaging and Chat Protocols, Vol. 20, Issue 4 IEEE Network
`pp. 16–21 (July/August 2006), available at
`https://ieeexplore.ieee.org/document/1668399
`
`U.S. Patent Application Publication No. 2002/0191797
`(“Perlman”)
`
`Cyph, Inc. v. Zoom Video Communications, Inc., No. 22-cv-
`00561-JSW, Dkt. No. 74 (N.D. Cal. Oct. 7, 2022), Dkt. No. 75
`(N.D. Cal. Oct. 11, 2022).
`
`Excerpts from Microsoft Computer Dictionary (Microsoft Press,
`5th ed. 2002)
`
`Table N/A—U.S. District Courts–Combined Civil and Criminal
`Federal Court Management Statistics (June 30, 2022),
`https://www.uscourts.gov/statistics/table/na/federal-court-
`management-statistics/2022/06/30-2
`
`Cyph, Inc. v. Zoom Video Communications, Inc., No. 21-cv-
`03027-RM-MEH, Dkt. No. 32 (D. Co. Jan. 27, 2022)
`
`Simon Singh, THE CODE BOOK: THE SCIENCE OF SECRECY FROM
`ANCIENT EGYPT TO QUANTUM CRYPTOGRAPHY (First Anchor
`Books Ed., Sept. 2000) (“The Code Book”)
`
`J. Fingas, Google+ Hangouts app hands-on, Engadget (May 15,
`2013)), https://www.engadget.com/2013-05-15-google-hangouts-
`app-hands-on.html
`
`11
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`IV. PERSON OF ORDINARY SKILL IN THE ART
`8.
`I understand that an assessment of the validity of the patent claims
`
`should be considered from the perspective of a person of ordinary skill in the art
`
`(“POSA”).
`
`9.
`
`I have been advised by counsel that a POSA is a person who
`
`possesses conventional wisdom in the art and is presumed to be aware of all
`
`relevant art at the time of the invention. To determine the appropriate level of a
`
`POSA, the following factors may be considered: (1) the type of problems
`
`encountered in the art; (2) prior art solutions to those problems; (3) the rapidity
`
`with which innovations are made; (4) the sophistication of the technology; and (5)
`
`the educational level of active workers in the field.
`
`10. As described in detail below, the ’070 patent purports to relate to
`
`encryption and it claims methods of conducting ephemeral communications over
`
`the network. Ex. 1001, Title; Claims 1–2. The ’070 patent relies on a combination
`
`of well-known elements such as ephemeral digital communications and the client-
`
`server architecture used for web-based applications, as I discuss in detail below.
`
`11.
`
`In view of the purported invention of the ’070 patent and my
`
`experience as a practicing engineer and researcher in this field since at least the
`
`early 2000s, it is my opinion that a POSA at the time of the alleged invention of
`
`the ’070 patent (approximately January of 2015) would have at least one year of
`
`
`
`12
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`
`undergraduate (or higher level) coursework, industry experience, or equivalent
`
`research experience in the field of cryptography, and at least one year of
`
`undergraduate (or higher) coursework, industry experience, or equivalent research
`
`experience in the field of instant messaging or chat applications or video- or audio-
`
`conferencing applications. This description is approximate, and a higher level of
`
`education or skill might make up for less experience, and vice versa.
`
`12. My analysis and opinions stated in this Declaration would remain the
`
`same even if a POSA were determined to have somewhat more or less education
`
`and/or experience than I have described above.
`
`V. LEGAL STANDARDS
`13.
`I am not an attorney, but in expressing my opinions in this Declaration
`
`and considering the subject matter of the claims of the ’070 patent, I am relying on
`
`certain legal principles counsel has provided and explained to me.
`
`A. Relevant Time Period for Invalidity Analysis
`14.
`I have been asked to assume that the priority date for the claims of the
`
`’070 patent is January 7, 2015, the filing date of a provisional application No.
`
`62/100,689. Therefore, for the purposes of this Declaration, I have analyzed
`
`validity from the perspective of a POSA as of January 2015.
`
`B. Claim Construction
`15.
`I understand that when evaluating the validity of patent claims, claim
`
`terms are generally given their ordinary and customary meaning, which is the
`
`
`
`13
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`
`meaning that the term would have to a POSA as of the effective filing date of the
`
`patent. I also understand that a POSA is deemed to read the claim term not only in
`
`the context of the particular claim, in which a claim term appears, but in the
`
`context of the entire patent, including the specification.
`
`16. My analysis and opinions in this Declaration do not depend on any
`
`particular construction of terms in the challenged claims. I have applied what I
`
`believe a POSA would consider to be the plain and ordinary meaning of all claim
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`terms. For the reasons discussed in further detail below, it is my opinion that the
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`prior art discussed below discloses the subject matter of the challenged claims
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`under any reasonable construction of the claim terms.
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`C. Anticipation
`17.
`I understand that patent claims may be invalid as “anticipated” in
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`view of a single prior art reference. Counsel has informed me that a patent claim is
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`anticipated by the prior art if each and every element of the claim is express or
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`inherently disclosed in a single prior art reference.
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`D. Obviousness
`18.
`It is my understanding that a patent claim is invalid if the claimed
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`invention, as a whole, would have been obvious to a POSA at the time of the
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`critical date—the effective filing date in the case of the ’070 patent—in view of the
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`prior art in the field and analogous fields.
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`19.
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`I understand that the following factors are considered as part of the
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`obviousness inquiry: (1) the scope and content of the prior art; (2) the differences
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`between the prior art and the claims at issue; (3) the level of ordinary skill in the
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`pertinent art; and (4) secondary considerations such as commercial success, long
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`felt but unsolved needs, failure of others, and simultaneous invention. I understand
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`that a “nexus” must be established between the evidence of secondary
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`considerations and what is both claimed and novel in the claim at issue for such
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`evidence to be relevant to the obviousness analysis.
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`20.
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`I understand that a reference qualifies as prior art for obviousness
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`purposes when it is analogous to the claimed invention. The reference is
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`analogous art (thus prior art) to the claimed invention if: (1) the reference is from
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`the same field of endeavor as the claimed invention (even if it addresses a different
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`problem); or (2) the reference is reasonably pertinent to the problem faced by the
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`inventor (even if it is not in the same field of endeavor as the claimed invention).
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`21.
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`I understand that obviousness may be shown by demonstrating that it
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`would have been obvious to modify what is taught in a single piece of prior art, or
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`to combine the teachings of more than one prior art reference, to create the claimed
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`invention. In determining whether a piece of prior art could have been modified,
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`or combined with other prior art references or with other information within the
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`
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`knowledge of a POSA, the following are examples of approaches and rationales
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`that may be considered:
`
`a.
`
`b.
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`c.
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`d.
`
`e.
`
`Combining prior art elements according to known methods to
`yield predictable results;
`Simple substitution of one known element for another to obtain
`predictable results;
`Use of known technique to improve similar devices (methods,
`or products) in the same way;
`Applying a known technique to a known device (method, or
`product) ready for improvement to yield predictable results;
`Applying a technique or approach that would have been
`“obvious to try” (that is, choosing from a finite number of
`identified, predictable solutions, with a reasonable expectation
`of success);
`Known work in one field of endeavor may prompt variations of
`it for use in either the same field or a different one based on
`design incentives or other market forces if the variations are
`predictable to a POSA; or
`Some teaching, suggestion, or motivation in the prior art that
`would have led a POSA to modify the prior art reference or to
`combine prior art reference teachings to arrive at the claimed
`invention.
`I understand that the suggestion or motivation may come from such
`
`f.
`
`g.
`
`22.
`
`sources as explicit statements in the prior art or from the knowledge or common
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`sense of a POSA. I also understand that a motivation to combine may be found
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`
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`explicitly or implicitly in market forces; design incentives; the interrelated
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`teachings of multiple patents; any need or problem known in the field of endeavor
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`at the time of invention and addressed by the patent; and the background
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`knowledge, creativity, and common sense of a POSA.
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`23.
`
`I understand that the approaches and rationales listed above are not
`
`exhaustive. Other approaches and rationales may also support a conclusion of
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`obviousness.
`
`24.
`
`I understand that an invention that might be considered an obvious
`
`variation or modification of the prior art may be considered non-obvious if one or
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`more prior art references discourage or teach away from the line of inquiry
`
`disclosed in the reference(s). However, for purposes of assessing obviousness, a
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`reference does not “teach away” from an invention simply because the reference
`
`expresses a general preference for an alternative invention. It is my understanding
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`that the doctrine of teaching away requires an indication that the combination
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`should not be attempted, because, for example, the combination would fail and/or
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`be inoperative for its intended purpose.
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`VI. SUMMARY OF OPINIONS
`25.
`It is my opinion that claims 1 and 2 of the ’070 patent are obvious
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`based on the online article titled “TinyChat Makes Creating Disposable Chat
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`
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`Rooms A Breeze” (“Wauters”; Ex. 1005) in combination with U.S. Patent No.
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`6,564,261 (“Gudjonsson”; Ex. 1007).
`
`26.
`
`It is also my opinion that claims 1 and 2 of the ’070 patent are obvious
`
`based on the online article titled “Create temporary and disposable chat rooms with
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`Stinto” (“Kaushik”; Ex. 1006) in combination with Gudjonsson.
`
`VII. TECHNOLOGY BACKGROUND
`A. Cryptography and Encryption
`27. The title of the ’070 patent is “Method of Ephemeral Encrypted
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`Communications.” Ex. 1001, Title. It states that the “embodiments herein
`
`generally relate to cryptography, and, more particularly, to a method of ephemeral
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`encrypted communications.” Id., 1:60–62.
`
`28. Cryptography is the science, and art, of secret writing. One of the
`
`goals of cryptography is to prevent an unauthorized and unintended receiver from
`
`determining the content of the message being communicated. Ex. 1008, 306.
`
`29. Encryption is an example of an application of cryptography.
`
`Encrypting a message or data produces an unintelligible, scrambled message
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`(called “ciphertext”) by applying a key to a plain, original message (called
`
`“plaintext”). Ex. 1039, 14; Ex. 1008, 307. Decryption reverses that process—it is
`
`the process of unscrambling (or recovering) the scrambled message. Ex. 1039, 46;
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`
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`Ex. 1008, 307. Figure 4 of The Code Book schematically illustrates the encryption
`
`and decryption process:
`
`
`
`Ex. 1039, 26.
`
`30. One of the benefits of cryptography is that only the key needs to be
`
`kept secret from unauthorized parties. Id.; Ex. 1008, 307. The encrypted message
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`(i.e., ciphertext) may be eavesdropped or intercepted by unauthorized parties
`
`during the transmission, but its content is protected by safeguarding the key that
`
`should not be exposed. Thus, only the authorized receiver, who has the right key
`
`(or who is able to deduce the right key), should be able to recover (i.e., decrypt) the
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`encrypted message. See Ex. 1039, 26–27. Any unauthorized receiver should not
`
`be able to deduce either the message or the unknown key.
`
`31.
`
`I note that notwithstanding the ’070 patent’s characterization of it
`
`being related to cryptography and encryption, it does not in fact describe or claim
`
`any cryptographic and encryption principles. In the ’070 patent, no message need
`
`be scrambled, or modified in any way; no encryption algorithm need be applied; no
`
`encryption key need be used; and no message needs to be recovered.
`
`
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`32. Rather, the ’070 patent criticizes the difficulties of, and risks
`
`associated with, using encryption keys in conventional encryption systems:
`
`“Conventional encryption systems are often difficult to use and thereby introduce
`
`weaknesses in the overall systems. For example, asymmetric encryption relies on
`
`complex mathematics applied to private a