Interview with Dr Robert Kahn, Co-Inventor of the Internet

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Shutterstock 16 and theNationalMedalofTechnology in1997. received thePresidential MedalofFreedom in2005 environment. Amonghisnumerous awards, DrKahn programs, mobilesoftware agents inthenetwork systems. Heisalsoco-inventorofKnowbot for interoperability ofheterogeneous information a digitalobjectarchitecture toprovide aframework More recently, DrKahn hasdevelopedtheconceptof DARPA’s Internet Program. protocol, andwas responsible fororiginating networking. Heisaco-inventoroftheTCP/IP Dr Kahn conceivedtheideaofopen-architecture States government’s Strategic ComputingProgram. Techniques Offi became Director ofitsInformationProcessing In 1972,DrKahn movedtoDARPA andsubsequently fi responsible forthesystemdesignofArpanet, MIT tojoinBoltBeranek andNewman,where hewas of Technology (MIT).Hetookaleaveofabsencefrom Electrical EngineeringattheMassachusettsInstitute Laboratories before hebecameAssistant Professor of 1964 respectively, DrKahn workedatAT&T andBell PhD degrees from PrincetonUniversityin 1962and the CityCollegeofNewYork in1960,andMA Following aBachelorofElectricalEngineeringfrom of theNationalInformationInfrastructure. for-profi Research Projects Agency(DARPA). CNRI isanot- term attheUnitedStates DefenseAdvanced (CNRI), whichhefoundedin1986aftera13-year the Corporation forNationalResearch Initiatives Robert E.Kahn isChairman,CEOandPresident of Initiatives Corporation forNationalResearch Chairman, CEOandPresident ofthe Robert E.Kahn 4 |2010 ITU News  rst packet-switchednetwork. t organization forresearch anddevelopment ce. There heinitiatedtheUnited  May 2010

CNRI about thishugesuccess? direct result ofthoseefforts.Howdoyoufeel the Internet co-inventor of Dr RobertKahn, Interview with www.itu.int/itunews Note: DrKahn’s fullinterviewisavailableonlineat it, goingforward. their country, andhowtheyplannedtodealwith discussing whattheimpactofInternetwason tions oftheworld,comingtogetherandpublicly when fortheﬁ Summit ontheInformationSocietyinGeneva, I’ve witnessedwasprobably atthe2003World The mosteye-openingofalltheeventsthat protocols were formallyadoptedforuse. community. It wasnotuntil1983thattheInternet nascent Internetwascreated withintheresearch col developmentbegan,and,bythemid-1970s, a world. In1973,theinitialworkonInternetproto- amazing toseewhathashappenedaround the some 40-oddyearsago,andstillgoing.It’s pretty like araging white-waterstream thatwegotinto bit likethiswholeInternetevolutionhasbeen because oftheraging rivers.Anditfeelsalittle your canoeintotheriveranditjustkeepsgoing

noeing whenIwasalittleyounger. You put Robert Kahn: Iusedtodowhite-waterca- ter networks.ThemodernInternetisthe computers ondifferent typesofcompu- world howtoconnectdifferent kindsof Some 40yearsago,youshowedthe rsttimeIgottowitnessallthena- Laureates of the 2010 ITU Award Interview

There are those who say that the under- You developed the digital object archi- lying architecture of the Internet may tecture concept. What is it exactly and not cope with ever-growing traffi c from how does it work? new, bandwidth-hungry applications. They advocate a clean-slate approach to the fu- Robert Kahn: The Internet, as origi- ture Internet. Are they justifi ed? Or is evolving the nally envisioned by me and others Internet the answer? that I worked with, involved moving bits around from place to place on a worldwide basis, without having Robert Kahn: From my perspective, the Internet to know details like what network the party was on, is a global information system that enables how to route data, and so forth. It was a conven- component structures like networks, computers and ient way to get information (as essentially undiffer- devices of different kinds to intercommunicate by entiated bits) from one place to another, reliably and passing information between them. The essence of rapidly. the Internet is the protocols and procedures that en- able this to happen. The protocols and procedures What occurred to me, a number of years ago, was were designed to be independent of the kinds of net- that we needed to take an additional step forward, working and computing components that comprise and begin to think about the Internet as a vehicle for it. managing information, as opposed to just delivery of undifferentiated bits. The problem with much of We have to keep evolving the Internet. And the the technology on the Internet today is that it is a way to evolve it is by integrating with or building on function of other technology that’s available on the what’s there. I don’t think you need to destroy what Internet. To give you an example, when I fi rst start- exists in order to create a better future. When the ed in computer networking, the way we addressed original computer networks were developed, they computers was by the wire that the computer was weren’t developed by destroying the telecommuni- connected to — on the one and only network in cations infrastructure. Where we are today with the existence. When we got to multiple networks, then Internet, we can do the same thing by leveraging the that wire might actually go to another network, and capabilities that are there to build new and better, so it wasn’t suffi cient to say “send it out on that more powerful, more relevant applications for the wire”, you had to say “then what? Where else would future and more relevant infrastructure to support it have to go?” So we created the notion of IP ad- those applications. dresses to identify the machines, regardless of where they were. And then we had to create simple ways A clean slate is not really practical. Maybe it once for people to remember those addresses. That was a was, when there was nothing to begin with. But kind of application, which is now well-known as the once you have something that’s widely deployed and domain name system (DNS). We made the decision in daily use by a large fraction of the world’s popula- to adopt the DNS in the mid-1980s; and it has served tion, you have to work with what you have. us well for more than two decades.

ITU News  4 | 2010  May 2010 17 © Alex Segre/Alamy 18 Laureates ofthe2010ITUAward every digitalobjectisuniquelyidentifi ital objects,and,bygivingeachaseparate identifi data structure wecalledthosedatastructures dig- represented intheformofapersistentlyidentifi that wehadwastoliterally identifytheinformation or willproduce different information.Sothenotion the vastmajorityofthemwilleithernolongerwork, URLs isnotverylong,andprobably withinfi cifi were resolvable through theDNSandthentospe- it wasimplemented:specifi the samethingsforyou.Butthattiedittoway the protocols behindthesceneswoulddoessentially type, intoaclickableversion,basedonURL,where somewhere andhavingtoknowexactlywhatkeys was toturnprocedural methods,likehavingtologin dures thatwehadbeenusingfordecades.Theidea there wasthatyoucouldessentiallysimplifyproce- When theWorld WideWeb wascreated, theidea c 4 |2010 ITU News  fi les onthosemachines.Thehalf-lifeofthese  May 2010 c machinenameswhich able. ve years ve able er, sumed fairlysoon. it seemsveryclearthattheseaddresses willbecon- making useofalimitedamountIPv4addresses, aged today, given thelackofgoodalternativesfor or maynotbesuffi pending onhowyoumanageIPv4addresses, itmay what’s putthepressure onIPv4addresses. Now, de- it becameclearthatwasinsuffi sion inlocalarea networks,particularlytheEthernet, that network.Thereality wasthat,withtheexplo- maining 24bitsenoughtodefi than enoughtoidentifyeachnetwork;andthere- 1973. At thetime,wethought8bitswouldbemore

tocol. We created the32-bitprotocol backin Robert Kahn: IPv4isa32-bitaddressing pro-

the transition toIPv6? col version4?Andwhatdoyouthinkof es basedonthecurrent Internetproto- Are wereally runningoutofIPaddress- cient. Butthewayit’s beingman- ne whichmachineon cet That’s cient. Interview Shutterstock

That was the motivation for creating IPv6, which object is over here now, or it’s in several places, and uses 128-bit addresses. It has been asserted that this please give me the object with the same identifi er. is enough to identify every atom in the universe. The conversion to IPv6 has been anything but straightfor- ward and simple. And getting adoption everywhere Will IPv6 bring us the “Internet of things”, in the world still seems a challenge in many respects. where for example, refrigerators will be But let’s assume that the transition to IPv6 is going to able to exchange information with su- happen as it seems almost inevitable. permarket shelves, where one can be in one’s of fi ce kilometres away and switch on and The real question is: are we going to cavalierly use off a microwave oven? IPv6 to identify absolutely everything in the Internet, or are we going to fi nd some other, more prudent, Robert Kahn: I don’t know that history gives long-term strategy to do that? For example, if I run us any good guidance as to what to expect in a system that contains a number of these digital ob- these cases. Usually, initial views of what a techno- jects I was talking about, suppose it’s got a trillion logical future will look like are wrong. For example, digital objects in one of these systems, one possibility in the history of telephony, there’s quite a bit of text is to give every one of those objects an IPv6 address. that’s been written about Alexander Graham Bell, But to me, that’s a very foolish use of these address- who is credited with the discovery or the invention of es, because IPv6 is also used for routing purposes, in telephony in the United States, thinking that it would part. It makes for a much more complex system than be a very good means for getting concerts into the if you just say, this particular item that I’m looking home. Well, do you know anybody that listens to for, this digital object, is at a system that’s got a given concerts over the telephone today? History is replete IPv6 address, and then once you get to that system, with examples where the initial view of people as to give me the object that’s got this unique identifi er, what might happen turned out to be wrong, and in which has nothing to do necessarily with IPv6. And time more socially effective means of using the tech- now if that object moves, you simply say, well, the nology emerged.

ITU News  4 | 2010  May 2010 19 Laureates of the 2010 ITU Award Interview

In the context of IPv6, ultimately, whether we are We were thinking of using “knowbot service sta- talking about the Internet of things or identity man- tions”, which (among other things) would be respon- agement for individuals, the bottom line is that we sible for injecting mobile programs into the Internet, are talking about information about those entities and for accepting mobile programs originated else- or individuals. All these questions revolve around the where and running them. So multiple programs same set of issues: How do you get to the informa- could show up and interact with each other, and tion? What do you do with the information? Is it ac- these programs could somehow, all together, ﬁ gure curate? Can you trust it? out the answer to a question, or carry out a task. It’s still pretty much waiting to happen on a larger scale.

Tell us more about Knowbots and the In the early 1990s, instead of proceeding down the “handle system” that you created. knowbot path, I decided to focus on the case where the mobile component was removed from the pic- Robert Kahn: One of the people I ture. The digital object architecture is what resulted. worked with for a long time in the It was assumed that these digital objects would be networking area is Vint Cerf, who’s also gotten a stored in accessible locations on the Internet called lot of publicity for the work he and I did with the repositories, and that you could access information Internet. Vint worked with me at DARPA for many in these repositories solely by virtue of knowing the years, he left brieﬂ y to go to MCI, and then he joined me again, back as employee number two when I started CNRI; he was at CNRI for another eight years or so after that.

During that period, we got quite interested in the

idea of ﬁ nding and managing information on the © Larry Lilac/Alamy Internet by virtue of sending out mobile programs that could execute in different places — you could task them to carry out various objectives for you. One major concern we had was that organizations would not want a mobile program that somebody else had written to just show up on their computers and execute. I suppose it seemed like an open invitation for viruses to show up, or worse.

identifi er of the object. So you didn’t have to worry mation systems that have reasons to interoperate, about what technology base it was on now or at to be able to interoperate without having somebody any point in the future because presumably, if im- specifi cally fi gure out ahead of time, for every pos- plemented properly, it could all support this kind of sible interaction, how they should do it? a notion.

A way was needed to resolve identifi ers to locations Your fi nal thoughts? and other useful information, like the ability to vali- date information including identity. This latter abil- Robert Kahn: The world is increas- ity translates to getting public keys for an individual, ingly connected. The coming dec- who could then verify information with a private key, ades are going to be as exciting as the past or authenticate information, or access the object’s decades have been, probably in dimensions that we terms and conditions. So, the whole notion of the don’t really know how to predict or envision. It is ulti- digital object architecture was based on a more static mately the creativity of the human spirit that is going view of these mobile programs. While it was antici- to drive and fuel this, and anything that we can do pated that it could be used in a mobile environment, to essentially stimulate that, and invigorate it, and this was not the initial focus of this work. enhance it, will probably help to come up with new and better ways of dealing with our societal needs Privacy becomes important in this context. There are going forward. search engines on the Internet today that allow you to locate things that are publicly accessible, for example on the web. But that’s not likely to help you fi nd your medical or fi nancial records. The question of privacy is a small part of the larger issue that I really think the digital object architecture was intended to address: How do you get different kinds of infor-

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