The (R)evolution of the Internet Protocol Suite

Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest

The implied trust and belief in collaboration works

well when all parties involved have a shared goal. In the

case of the Internet protocol suite, that shared goal has

been the development of a scalable and functional global

network. However, the parameters of that network have

changed as it has transitioned from research project to

commercial venture to indispensable infrastructure.

Not all actors share the same goal. Not all goals have

positive outcomes for all involved. However, many of the

key underlying Internet protocols have not evolved to

address the emergence of these competing goals. Many

protocols have either limited or no protections against a

variety of attacks. Many operators are wary of enabling

security on some protocols because of a fear of interoper-

ABSTRACT

The allegations of widespread, pervasive monitoring of Internet traffic have ignited new thrusts to

strengthen the core protocols that underpin the Internet. Many of these protocols were developed

in a time when the community of interest was small and trust between the members was rock

solid. Such trust led to protocols that did not protect against actions such as denial-of-service

attacks, man-in-the-middle attacks, or pervasive monitoring, leading to the widespread use of

relatively insecure protocols. The Internet is no longer a homogenous, all-trusting community, and

the underlying protocols are being examined to determine whether they should undergo poten-

tially drastic changes to address the threats. This article highlights some of the key changes being

considered and describes their possible benefits and drawbacks. The impact of these changes

could be beneficial to Internet users concerned about indiscriminate eavesdropping but could

also prove costly to innocent network operators/users who have developed operational and use

models based on the older, less secure designs of the protocols.

The (R)evolution of the Internet

ProtocolSuite

Brian K. Haberman

INTRODUCTION

The origins of the Internet arose from a classically

academic research project. Despite the ever-growing size

of the Internet research community, the protocols devel-

oped all retained a core aspect from the beginning—

implicit trust. The Internet was able to grow because

independent teams of researchers and developers trusted

the information being shared across their common

medium. Collaboration, and the trust it grew, sped inno-

vation at rates faster than could have been imagined.

A classic example of this collaborative environment is

the Robustness Principle attributed to Jon Postel:

“Be

liberal in what you accept, and conservative in what you

send.” The Robustness Principle epitomizes the belief

that all involved are working toward a common goal.

The (R)evolution of the Internet Protocol Suite

Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest

These trade-offs highlight the tricky nature of retrofit-

ting security into existing, deployed, and widely used

network protocols. It should be noted that these three

cases are representative of a broader effort within the

IETF to strengthen new and existing network proto-

cols. Other protocols such as Internet Protocol version 6

(IPv6), e-mail, Network Time Protocol (NTP), Border

Gateway Protocol (BGP), and Transport Layer Security

(TLS) are all being studied or revised to strengthen their

security posture.

Hypertext Transfer Protocol 2.0

In 2015, a large majority of Internet web traffic is car-

ried via version 1.1 of the Hypertext Transfer Protocol

(HTTP),

which was standardized in 1999. The IETF is

currently working on a replacement for HTTP 1.1, des-

ignated HTTP 2.0. As a part of the discussion of the

structure and semantics of HTTP 2.0, consideration is

being given to encrypting all web traffic. In today’s Inter-

net, only sensitive web traffic (e.g., online banking) is

encrypted. Users recognize this by the use of Uniform

Resource Locators (URLs) that start with HTTPS://, as

opposed to the unprotected websites that are accessed

via HTTP://. The proponents of such a change argue that

encryption is one way to mitigate pervasive monitoring

of Internet web traffic. Several key arguments can be

made that justify having all web traffic transit encrypted

connections between web servers and clients (Fig. 1).

The primary argument for encrypting all HTTP 2.0

traffic is that users now expect their data to be protected

in the face of pervasive monitoring. The mounting alle-

gations of widespread data collection by a variety of gov-

ability issues or an unwillingness to increase costs with-

out some return on investment. There are a myriad of

reasons for the general lack of security in key protocols

that underpin the Internet.

With the emergence of allegations of widespread, per-

vasive monitoring, segments of the Internet population

have reacted swiftly to address the shortcomings in the

protocol suite. Bruce Schneier, a noted security researcher,

challenged the Internet Engineering Task Force (IETF),

the body charged with maintaining the Internet protocol

specifications, to strengthen the core protocols against

“wholesale spying.”

In response, the IETF developed a

“statement of principles” in 2014 designed to guide proto-

col development going forward.

Two items within that

document are worth noting specifically:

• The IETF deﬁnes pervasive monitoring as a wide-

spread attack on privacy.

• The IETF will work to mitigate pervasive monitoring.

The IETF began work to mitigate pervasive monitor-

ing almost immediately after Edward Snowden’s initial

allegations of pervasive monitoring,

before members

completely agreed on the statement of principles docu-

ment. Subsets of the community immediately began con-

sidering potential changes in key protocols in response

to the allegations.

The remainder of this article describes three rep-

resentative efforts to minimize the impact of perva-

sive monitoring on Internet users. These efforts were

selected because of their direct impact on everyday users.

As a part of the discussion, this article discusses the key

benefits and key drawbacks of the proposed approaches.

Figure 1. Potential change to web encryption during the transition from HTTP1.1 to HTTP2.0.

B. K. Haberman

Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest

business reasons, which require a man-in-the-middle

capability, would require a new operational paradigm.

A subset of the community believes it is inappropriate

to encrypt all data given that most data are not sensitive

(e.g., sports scores). It could be considered excessive to

establish the necessary security association between the

web server and the client to exchange data that are clearly

meant to be public. Additionally, the existing TLS proto-

col is not designed to handle newer forms of web content

such as video and other multimedia, which could make

encrypting all web traffic impossible in the near term.

A third counter to encrypting all web traffic is the

issue of cost. Encryption technology is complex and

requires additional resources (bandwidth, processing,

etc.). Current web encryption relies on a certificate-

based infrastructure that some see as brittle and already

corrupted by entities performing pervasive monitoring.

On the evolving side, many view the use of TLS as infea-

sible for the Internet of Things. Expecting a light switch

to have the processing capability to instantiate and

maintain security associations seems excessive to some.

At the time of this writing, the direction of the

HTTP 2.0 specification has not been decided. The

above-described (and other) trade-offs have elicited

thoughtful discussion of technical, ethical, legal, and

political issues that will impact the standardization

effort. Clearly, the people involved in HTTP 2.0 are

carefully considering all of the issues related to pervasive

monitoring and recognize the impact their decisions will

have on the Internet.

DOMAIN NAME SYSTEM PRIVACY

The Domain Name System (DNS)

may be one of

the most important pieces of Internet infrastructure

that most people take for granted, ignore, or do not fully

understand. Almost all Internet activities begin with

a DNS query to map a target destination’s name (e.g.,

www.ietf.org) to its Internet Protocol (IP) address, allow-

ing the client’s network stack to correctly address the

connection request. The DNS is a hierarchical distrib-

uted database that maps domain names with a variety of

information (including IP addresses). The maintenance

of the mapping records is delegated to the authorita-

tive name servers designated for each domain name.

Although there are several modes of operation, the fol-

lowing is a representative model of DNS exchanges:

1. A client (stub resolver) issues a query for

www.example.com to its local recursive resolver.

2. The recursive resolver performs a series of DNS que-

ries, starting at the root of the DNS hierarchy, until it

receives an answer from the authoritative name server.

3. The recursive resolver caches the answer for future

use and sends the answer back to the client.

ernments have sensitized users to the potential loss of

privacy. From an interoperability perspective, it is more

feasible to standardize the encrypted data exchanges

within the protocol than it is to expect ad hoc mecha-

nisms to be developed and widely used. By incorporating

encryption into all web exchanges, the HTTP 2.0 stan-

dard would simplify the operation of the protocol and

protect the privacy of all data.

The next argument is one of economics. Currently,

pervasive monitoring is cheap and easy. Bruce Schneier’s

challenge to the IETF included a goal to “make surveil-

lance expensive again.”

If HTTP 2.0 encrypts all traf-

fic, as the percentage of web traffic carried by HTTP 2.0

increases, the less practical widespread surveillance

becomes. There is an economic reality on the users’

side as well. It is generally agreed that the user inter-

face for web security is hard for most users. The use of

HTTPS:// URLs does not necessarily mean that all traf-

fic is encrypted. By moving to a privacy-always model,

users do not risk their financial future to a clunky user

interface. A single model of operation is much simpler to

develop, maintain, and operate.

A third argument in favor of encrypting all web

traffic is the nebulous definition of privacy.

Privacy

has become an important concept, but experts cannot

agree on a definition of privacy or on which information

needs to be kept private. This debate makes choosing

what should be private and what should not be private

context dependent. However, the transport of informa-

tion should not be tied to context. The application

delivering the information should always err on the side

of protecting information. Accepting these two tenets

removes the need for any hard choices on the part of the

user or the content provider when sending data over a

web connection.

As with most technology decisions, there are trade-offs

and differing opinions. Although the above-described

advantages appear straightforward, an encrypted-always

web comes with incurred costs, potential drawbacks,

and dissenting opinions.

The biggest drawback raised with an always-encrypted

web is the impact it would have on existing infrastruc-

ture. Most notably, many Internet service providers

rely on the use of web caches to reduce the amount

of bandwidth needed to serve popular web content.

These devices inspect HTTP exchanges and cache the

returned content for use by other local users. Caching

can dramatically reduce the amount of network traffic

generated and speed up response time for popular con-

tent. If all web exchanges were encrypted, these cach-

ing devices would be unable to operate, increasing the

amount of network traffic and increasing the response

time. Services such as load balancers, malware scanners,

and content filters would also be adversely impacted by a

move to an encrypted web. Additionally, policy enforce-

ment devices used to limit web accessibility for legal or

The (R)evolution of the Internet Protocol Suite

Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest

resolver and authoritative name servers. The DNS Secu-

rity Extensions (DNSSEC)

only provide for informa-

tion integrity and authentication, not confidentiality for

information exchanges (see Fig. 2).

At the time of this writing, the IETF is actively dis-

cussing addressing the lack of privacy controls within

the DNS protocol. These discussions are focused on the

privacy risks for the user initiating the DNS requests in

the face of pervasive monitoring. As noted above, DNS

questions may be sensitive based on who is asking for a

particular DNS mapping. A passive observer can extract

from a DNS request going from the stub resolver to the

local recursive resolver:

1. The IP address of the requesting machine (which

may map to a speciﬁc user)

2. The exact DNS name being queried

3. The type of record being requested (e.g., a mail

server record)

The current DNS model levies differing requirements

for privacy based on the point where pervasive moni-

toring may be incurred. Traffic from the stub resolver

to a local recursive resolver will contain the exact DNS

name being queried as well as the IP address of the

specific machine making the request. However, if that

query is sent from the local resolver to the authoritative

name server, the requesting IP address is that of the local

resolver rather than of the original requester. That type

of separation may lend itself to different types of privacy

controls depending on what type of DNS resolver is

originating the DNS request. But that separation does

not always hold because it is quite easy for users to oper-

ate their own local recursive resolvers, rather than a stub

resolver, on their own machines.

The integral nature of DNS on the functioning of the

Internet makes the problem of confidentiality a difficult

one. DNSSEC eventually

gained traction because the

additional certificate infor-

mation was incorporated

as yet another DNS record

type, and resolvers that did

not support DNSSEC could

skip the validation. In other

words, the functionality

of DNSSEC did not affect

legacy devices. It is unclear

how confidentiality can

be incorporated without

impacting the operational

model of DNS. Many of

the pros and cons listed

for HTTP 2.0 also apply to

DNS confidentiality.

As with other Internet protocols, DNS was developed

with little security in mind. In fact, the information con-

tained within the DNS should be considered public. If

it were not, the Internet would not function as well as

it does because the name-to-address mapping function

underpins the entire Internet. How many users would

want to memorize the IP addresses of their favorite web-

sites? Treating all questions as equal has allowed DNS

to remain a relatively simple query/response protocol.

But, as mentioned, the rules have changed because of

the differing goals of the various Internet participants,

and protection of DNS data is being examined intently.

The public nature of DNS data allows network users

to efficiently reach the content of interest without

knowing anything about the topology of the Internet.

However, there are still privacy aspects to be considered.

The DNS does not provide users with a search capa-

bility. That means that the stub resolver has to know

what to ask for to receive a useful answer. So, although

the mapping of www.example.com to 2001:500:8d::53

is public information, the fact that a particular user

requested that mapping may be sensitive and should

be kept private. Additionally, the DNS is being used to

map more than just IP addresses to names. For example,

DNS records identify: (i) the mail server for a particu-

lar domain, (ii) DNS name servers for a target domain,

and (iii) security certificates for a target domain name

or IP address. Accessing those additional mappings may

reveal sensitive metadata about the user formulating the

DNS question(s).

The DNS protocol does not currently provide users

with any type of privacy protection for the questions

asked or the answers received. All DNS exchanges are

sent unencrypted and are visible to any entity capable

of examining packets in transit. That limitation is true

regardless of whether the exchange is between a stub

resolver and a recursive resolver or between a recursive

DNS

Resolver

Where’s www.medicalinfo.com?

Where’s www.onlinebank.com?

Where’s www.privatewebsite.com?

Figure 2. Intermediaries snooping on DNS exchanges build substantial profiles of users.

B. K. Haberman

Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest

to protect critical applications that are susceptible to

pervasive monitoring. As a starting point, the e-mail

(SMTP, IMAP, and POP), instant messaging (XMPP),

and web (HTTP 1.1) protocols will be used as the rep-

resentative application protocols mentioned in point

no. 1 above.

Around 1994, the IETF started requiring all pro-

posed standards to contain a Security Considerations

section. The premise of such a section was to facilitate

the discussion of security issues related to the proto-

col being specified. This discussion routinely mentions

means to mitigate the identified security issues related

to the protocol. Unfortunately, many documents

simply stated that IP security (IPsec) should be used to

mitigate these vulnerabilities. The problem with such

generic advice is that it was not useful. In some cases, a

description of how to use IPsec to mitigate a vulnerabil-

ity was missing. In other cases, specifications assumed

IPsec could protect against anything, when in reality, it

could not. In time, the phrase “just use IPsec” became

a punch line rather than a solution. To avoid a similar

situation with TLS, the UTA working group is formu-

lating a set of recommendations for the proper use of

TLS and the datagram version of TLS (called DTLS).

These recommendations currently discuss issues related

to versions of the protocols, cipher suites to use with

the protocols, capability negotiation, and public key

lengths. It is envisioned that such guidance will lead to

more robust implementations of TLS-protected appli-

cations and a wider use of TLS to protect against per-

vasive monitoring.

Unlike the previously described examples, the out-

come of the UTA effort appears much clearer. Many

application developers already have some semblance of

TLS support within their code bases. This clarity and

familiarity makes the outcome of the UTA working

group more useful in the short term and more likely to

be adopted quickly by both the development community

as well as the user community.

DISCUSSION

Whether one calls these protocol changes evolu-

tionary or revolutionary, one thing is clear. There is a

potential sea change over the horizon. While some have

argued that pervasive monitoring has been occurring

for a long time, these recent allegations have become

a catalyst for change within the Internet community.

The currently proposed changes are only representative

of the potential changes being considered for the Inter-

net protocol suite. The IETF’s statement of principles

on the topic of pervasive monitoring sums up the new

model of network protocol standardization: “The IETF

will work to mitigate the technical aspects of PM [perva-

sive monitoring], just as we do for protocol vulnerabili-

ties in general.”

• Not all requester’s IP address to queried domain

name mappings are sensitive.

• Fundamental changes to the protocol will impact

legacy devices.

• Additional infrastructure for conﬁdentiality

approaches (e.g., encryption) incurs costs.

These issues and the potential privacy gains from

augmenting DNS will drive the discussion within the

IETF. The threat to privacy from pervasive monitoring

of the DNS is still not completely understood. In some

instances, pervasive monitoring provides protection

from threats such as malware.

However, the decisions

made at the DNS protocol level need to consider all

aspects and threats to privacy.

USING TLS IN APPLICATIONS

Many application protocols have defined methods for

using TLS to encrypt traffic and authenticate one or both

endpoints in a communications session. However, there is

significant diversity in the definitions of those methods as

well as variations in the requirements for the use of TLS.

This diversity has led to confusion within the implemen-

tation community, resulting in a lack of interoperability

and deployment of TLS-protected applications.

The Using TLS in Applications (UTA) working

group within the IETF was chartered to address this

confusion and simplify the lives of developers wanting to

use TLS in application protocols. If standardized meth-

ods of use are available, it will be easier for application

programmers to develop interoperable implementations

of TLS-enabled services. As a starting point, the UTA

working group has four preliminary work items to facili-

tate the use of TLS within applications protocols:

1. Update the deﬁnitions for using TLS over a set of

representative application protocols. These deﬁni-

tions include communication with proxies, between

servers, and between peers, where appropriate, in

addition to client/server communication.

2. Specify a set of best practices for TLS clients and

servers, including but not limited to recommended

versions of TLS, using forward secrecy, and one or

more cipher suites and extensions that are manda-

tory to implement.

3. Consider, and possibly deﬁne, a standard way for an

application client and server to use unauthenticated

encryption through TLS when server and/or client

authentication cannot be achieved.

4. Create a document that helps application protocol

developers use TLS in future application deﬁnitions.

The above-described work items should provide

application developers strategic guidance for using TLS

The (R)evolution of the Internet Protocol Suite

Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest

Although these dramatic changes are unfolding,

they are not without cost. As mentioned earlier, some

of these changes are being resisted primarily because

of the impact they will have on current industries, net-

work operators, and users. Several industries have blos-

somed in the current network environment where most

network traffic is free for the analysis. Marketing com-

panies analyze network traffic so that they can provide

targeted ads. Malware and spam detection devices per-

form deep packet inspection of transit traffic within net-

works. Some Internet service providers redirect users to

advertisement-oriented web servers when they mistype

domain names. These business practices are predicated

on being able to inspect network traffic. Changes to net-

work protocols to enhance privacy, generally through

some type of encryption, have the potential to dramati-

cally impact such business models.

Network operators leverage a number of pervasive

monitoring techniques in the name of efficient network

management. A variety of protocols and tools are widely

used that assess bandwidth consumption, traffic profiles,

and trends. Any significant increase in the amount of

encrypted traffic could affect network operations in

ways such as:

1. Increasing bandwidth consumption from both secu-

rity association signaling and per-packet overhead

2. Increasing packet processing costs for encrypted

control and management trafﬁc; and

3. Increasing operational costs to overhaul network

management models.

Outside of these costs, network operators will be on

the front lines of protocol interoperability issues. Tran-

sitioning protocols is recognized as a difficult task. Users

and network services are not all managed by one entity,

so legacy interoperability will be a critical component of

making enhanced protocols viable.

One of the most significant concerns mentioned in

relation to increased privacy protections within network

protocols is the impact on the everyday user. Most Inter-

net users do not have an understanding of the exist-

ing security models in use today. The appearance of a

lock icon on their browser makes many people feel they

are secure. It is unclear how people will react if their

HTTP 2.0-capable browser indicates that all sessions are

“locked” or the browser does not make any indications

at all. Will users recognize that they need to be involved

in determining when certain information should be

considered private? There will be a large human factors

aspect to any dramatic shift in the network protocols if

those changes expose new decisions to users.

Despite these costs, the network protocol environ-

ment appears poised for change. The lack of a common

goal among all stakeholders will preclude the standard-

ization of network protocols without security as an

The key word in the above statement is technical.

The Internet community recognizes that there are mul-

tiple facets to the pervasive monitoring issue (technical,

political, social, legal, etc.) but realizes the technical

issues can be worked strictly from an engineering per-

spective. Even within the purview of network protocol

standardization, there are numerous avenues of interest

for technical contributions.

As noted in the earlier examples, significant work

is ongoing to re-engineer protocols to strengthen them

against pervasive monitoring. Historically, far too little

effort has gone into the security aspects of network pro-

tocols. That mindset appears to be changing. With such

re-engineering, additional work will need to be under-

taken to address both the interoperability issue with

legacy systems and the potential impact on the opera-

tional paradigms that were developed while using older,

less secure versions of the protocols.

Part of the weakness in current network protocols has

been the lack of attention given to protecting private

information. That lack of attention is generally caused

by two things: first, protocol engineers focusing only on

the on-the-wire protocol operation and not considering

the value of the information being shared; and, second,

the complexity of what privacy entails. The former can

be rectified as a part of the standardization process by

including privacy-related issues in the review process. In

fact, that change has begun as more reviewers provide

feedback on privacy issues with protocol proposals being

put forth for publication. The latter issue is one of educa-

tion, and that has begun as well with the publication of a

privacy considerations document for Internet standards.

As more protocol engineers understand privacy issues

and consciously consider them in their design decisions,

newer network protocols will be less likely to leak private

information as a part of normal protocol operation.

Many people recognize that openness can create

an environment of trust. To that end, there has been

an increased interest in ensuring that as much of the

network infrastructure is open as possible. Although

most readers will recognize terms such as open source

and open standards, these terms do not cover the entire

spectrum. Open protocol standards allow implementers,

researchers, and users to review the protocol operation

as required to ensure correct protocol behavior. Open-

source software allows people to examine the code to

ensure correct operation and behavior. Openness applies

to security as well. Transparency in all aspects of the

security model or mechanism provides accountability.

That accountability allows users to exercise checks and

balances that can determine the effectiveness of the

security mechanism and expose any potential abuse of

the security mechanism. A paradigm of openness will

require changes in the behaviors of both people and

institutions. Currently, that paradigm shift appears to be

gaining momentum within the networking community.

B. K. Haberman

Johns Hopkins APL Technical Digest, Volume 33, Number 1 (2015), www.jhuapl.edu/techdigest

integrated component. That change will not come over-

night, but the consensus is that such a change is needed.

The impact of the change is still an unknown as the full

spectrum of the change is still evolving. Because perva-

sive monitoring is viewed as more than just a technical

problem, other changes from outside the technical com-

munity can affect the technical aspects being addressed

within the standards community. From all appearances,

the evolution of the Internet protocol suite has begun.

Its effect on the current Internet is to be determined.

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Internet Engineering Task Force (1989).

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Internet Engineering Task Force (2014).

THE AUTHOR

Brian K. Haberman is a member of the Principal Professional Staff and a research scientist in the Tactical Wireless

Systems Group. His research interests include IPv6, IP multicast, ad hoc and sensor networks, routing, routing protocol

security, and network architecture. He currently serves as an area director within the Internet Engineering Task Force

and is a member of the ACM. Prior to working at APL, he held network protocol development, platform design, system

architecture, and research positions for several networking companies. His e-mail address is brian.haberman@jhuapl.edu.

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