回复:RE: RE: [itu-sg16] Q22 Question - SATC - sg16-avd

27 Sep 2008

      Paul,
you are a smart hacker, DPI can not stop you,:-).
DPI hardly can tackle encrypted communication now, but this do not prevent DPI from getting more and more market deployment. Maybe someday,most internet communications will be encrypted to circumvent such kind of inspection, then I think new techonolgies will be devised to face these embarrassment.
Anyway, I think content protection like copyright protection is a interesting area that worth doing something.
******************************************************************************************
 This email and its attachments contain confidential information from HUAWEI, which is intended only for the person or entity whose address is listed above. Any use of the information contained here in any way (including, but not limited to, total or partial disclosure, reproduction, or dissemination) by persons other than the intended recipient(s) is prohibited. If you receive this email in error, please notify the sender by phone or email
 immediately and delete it!
 *****************************************************************************************
----- 原邮件 -----
发件人: "Paul E. Jones" paulej@packetizer.com
日期: 星期五, 九月 26日, 2008 下午2:06
主题: RE: RE: [itu-sg16] Q22 Question - SATC
收件人: 'zourong 52447' zou.rong@huawei.com
抄送: ''Noah Luo ' ("罗忠")' noah@huawei.com
...
Rong,
You are right that current file sharing networks (mostly) do not use
encryption.  But, they would if necessary.  In fact, I have a file 
sharingprogram on my machine that does offer encryption for file 
transfers.  If
such measures were employed to block traffic, I think all tools 
would simply
encrypt contents by default.  One could try to guess the contents 
of the
encrypted file by looking at such things as the file length, etc., but
nothing is perfect.
I can accept that no solution is perfect, but I honestly believe 
that this
one just will not work in practice.  I used to be one of the kids 
in high
school that would remove copy protection from software products by 
manuallyaltering machine code right on the disk.  I even wrote my 
own utilities to
allow me to modify code on disk -- and I wrote that in assembly 
language.
Lawful intercept works for a few reasons:

Most criminals are stupid and use public communication
Almost everybody connects to a carrier network to carry voice --

so
carriers become a natural intercept point
Lawful intercept does not work for smart criminals.  They use secure
communication channels.
But, we can't really compare this to Lawful Intercept.  Normal 
users just
use the tools that are out on the Internet.  If I were writing a file
sharing program and encountered packet filtering issues, I would 
immediatelyemploy encryption.  I could write the necessary code in 
an afternoon and
effectively defeat systems employed to stop it. And, those systems 
are all
very expensive hardware-based solutions that would be rendered 
useless.
Honestly, I'm not trying to be an irritant :-)  But, I'm quite 
doubtful that
any DPI scheme can work to stop the proliferation of copyrighted 
material.It's simply too easy to devise a work-around in software 
and, while the DPI
logic can get more complicated, the algorithms in a PC-based 
application can
be revised and updated far more rapidly.  Heck, I would even have 
the packet
encoding algorithms written in such a way as to be downloadable 
when the
program starts.  That way, the newest encoding algorithms are always
available every time the program starts.
Paul
...
-----Original Message-----
From: zourong 52447 [mailto:zou.rong@huawei.com]
Sent: Thursday, September 25, 2008 11:48 PM
To: Paul E. Jones
Cc: 'Noah Luo ' ("罗忠")
Subject: 回复:RE: [itu-sg16] Q22 Question - SATC
Paul，
Sorry for taking so long to respond to your mail because I have
taken a
...
long vacation and then followed by a busy business trip.
I agree with you that the method proposed in my contribution AVD
3541> is not a perfect solution to the copy-right protection 
issue. It could
...
not handle the case that the communication is encrypted ?C as you
mentioned.
In fact, I think it is one of the limitations of DPI technology. The
signature-based DPI technology could not inspect the encrypted data
flow. But I still believe that it could work and do something
useful in
...
a broad range of use cases, just like the lawful interception: it
hardly could handle the encrypted communication but it still can
work> well.
...
As to your suspicion   whether it could work in a practical
situation.> I hope it could work in some public file sharing 
scenarios especially
...
the P2P file sharing. Why I put my effort in study the P2P file
sharing> scenario is that P2P file sharing is the most popular 
file sharing
...
tools nowadays and most of the files being shared are multimedia
files> and many of them are pirated.
...
P2P file sharing has one important character that could be
exploited:> the file information is almost public. It should let 
people know what
...
the resource is, for example, the file name, file type, file
size, file
...
hash value etc., these file describe information will be
transmitted in
...
the file sharing control messages and could be intercepted by SATC.
Another character of P2P file sharing is that it seldom uses
encrypted> communication because that will bring burden to its 
efficiency and
...
affect its popularity.
Then to the question of “good database” and “suspicious database”.
What
...
I want to do is a multi-level inspection and filter. It maybe
works as
...
following:
Extracting_file_information();
Searching_good_database();
If(got matched item)
{
   Compare_signature();
   If(match)
   {
        	It is copy-righted file and transmitted;
         }
         Else
         {
           Searching_suspecious_database();
           If(match)
           {
        	It is a known pirated version, stop it;
             }
            Else
            {
               It maybe a new pirated version, record it temporality
and notify the content provider to make sure and to update the
suspicious database ;
          Transmit_flow();
            }
         }
}
In this multi-level filtering, the first level ”good database”
filtering can be performed with the help of  a reasonably small-
sized> database  and achieve rather fast processing speed, the 
second level
...
”suspicious database” filtering may require a much bigger
database. But
...
only searching only a part of them each time  also could yield
reasonable processing speed.
So that is what I want to do, only those truly pirated file sharing
will be stopped right now, other suspected file sharing will be
recorded and let the technicians to do further judgment.
***********************************************************************> *******************
...
This email and its attachments contain confidential information
from> HUAWEI, which is intended only for the person or entity 
whose address
...
is listed above. Any use of the information contained here in
any way
...
(including, but not limited to, total or partial disclosure,
reproduction, or dissemination) by persons other than the intended
recipient(s) is prohibited. If you receive this email in error,
please> notify the sender by phone or email
...
immediately and delete it!
***********************************************************************> ******************
...
----- 原邮件 -----
发件人: "Paul E. Jones" paulej@packetizer.com
日期: 星期五, 九月 12日, 2008 上午11:50
主题: RE: [itu-sg16] Q22 Question - SATC
收件人: 'Noah Luo(罗忠)' noah@huawei.com
抄送: zou.rong@huawei.com
...
Noah,
I have no objection to exploring the idea.  But, I'm 100% certain
it will
not work :-)  I am various serious about that.  When I was a
teenager, I
spent a lot of time removing copy protection from software
(actually> > modifying the machine code by hand), hacking computer 
systems,> > etc.  Even
...
...
when I was in college, I had a professor who called me an
unscrupulous
...
hacker.  He was only half joking.  He had a real admiration
for my
...
...
technicalability, but wasn't very happy with some of the
hacking I
...
...
used to do.
Still, he recognized that I was a good kid who just wanting to
explore and
learn as much as possible.
I used to play with viruses.  I would even write some that would
not cause
harm -- they would never replicate.  Rather, they would just run
in the
background of machines that I placed them on, loading into the
system at
boot time.  I still have a collection of probably 1,000 virus
files, many
with the assembly code.
The short of it is that I have a lot of experience at this
sort of
...
...
thing.While I don't do the hacking I did when I was a kid, I can
guarantee you
that there will be some just ready to tackle the challenge of
breaking any
kind of defense like what this standard intends to provide.  And,
as I said,
the simplest thing to do is simply use TLS.  In fact, I could
exchange
...
pirated music or video via e-mail between my server at home and
anybody else
who uses TLS -- my servers all use encryption.  But, we can
certainly employ
simpler techniques.  For example, I could do this:
K = 256_bit_random_key;
   while(not_end_of_file)
   {
       M = read_file(16 octets of the file);
       Y = M XOR K;
       transmit_message(Y);
       K = rotate_right(K);
   }
   transmit_message(K);
This is a very simple and extremely fast encryption algorithm that
willactually transmit the session key at the end.  So, there
is no
...
...
secrethidden, but it avoids the need of exchanging encryption keys
some other way.
This is not a flawless procedure, though.  In fact, this is very
easy to
"crack", since we're just XORing the bits of the input stream with
the key
and then rotating the key 1 bit after each message.  If an input
stream had
a number of 0s, then the key would appear as repeated data blocks
that can
be easily identified by a cryptography person.  Heck, even I would
recognizethe pattern.  But, this might still be complex enough to
avoid real-time
detection of pirated content.  But, I could just as easily use AES
and
...
*really* encrypt the media and place the 256-bit initialization
vector and
key at the end of the transmitted media stream :-)
Anyway, like I said-- I have no objections to studying this.  I
just am just
a firm believer that it will only stop the casual pirates: those
who want to
use gmail.com or something to send an e-mail containing music.
It
...
...
would not
stop software designed for secure file exchange, either person-
to-
...
...
person or
across file sharing networks.
My primary concern now is with the wording in the report.  Rong
felt it was
OK, but I still think it's wrong.  It says:
"... if SATC finds a data stream carrying content failing to match
a known
signature, it will block the stream or mark it as being
suspicious.”> >
...
...
Worded another way, this sentence says: "if the data stream
contains an
unknown data stream, block the data stream."
Now that would actually work to block pirated content, because you
essentially only let known data through the network.  But, I don't
thinkthat is the intent, and it's definite not what the AVD
document said.
Paul
...
-----Original Message-----
From: Noah Luo(罗忠) [mailto:noah@huawei.com]
Sent: Thursday, September 11, 2008 5:46 AM
To: 'Paul E. Jones'
Cc: zou.rong@huawei.com
Subject: 答复: [itu-sg16] Q22 Question - SATC
Dear Paul
Thank u very much for your good analysis and insightful
comments on
...
...
...
this
specific aspect SATC.I will work together with Rong and come up
with a
...
solution as to how the Q22 meeting report will be appropriatedly
reworded.Based on C3541 itself,actually, Q22 meeting report just
faithfully
reflects the basic idea of the scheme described.But if we
also take
...
...
...
into
account the supplementary information Rong provided in his mail
to you,
...
then
Q22 report may need incorporate some more information.
As for your questions regarding the feasibility of using
signature> > > matching
...
...
...
to block pirated contents transmission.I agree that we need more
careful
consideration.I think it will be ideal if  more contributions
will be
...
submitted by Rong to the next SG16 meeting so that we can
have more
...
...
...
extensive discussion.My personal feeling is that it is a rather
innovative
idea to use this kind of techniques to block illegally
distributed> > > contents,
...
...
...
but there may still lack some feasible technical points to
enable this
...
idea
to be transformed into a practical solution.
Paul, do you think this arrangement will be okay?
Best Regards
Noah
华为技术有限公司  huawei_logo
地址：深圳市龙岗区坂田华为基地 邮编：518129
http://www.huawei.com

...
...

...

本邮件及其附件含有华为公司的保密信息，仅限于发送给上面地址中列出的个人
或群
...
...
...
组。禁
止任何其他人以任何形式使用（包括但不限于全部或部分地泄露、复制、或散
发）本
...
...
邮
...
件中
的信息。如果您错收了本邮件，请您立即电话或邮件通知发件人并删除本邮件！
This e-mail and its attachments contain confidential information
from> HUAWEI, which
...
is intended only for the person or entity whose address is
listed> > > above. Any
...
...
...
use of the
information contained herein in any way (including, but not
limited to,
...
total or partial
disclosure, reproduction, or dissemination) by persons other
than the
...
intended
recipient(s) is prohibited. If you receive this e-mail in error,
please> notify the sender by
...
phone or email immediately and delete it!
-----邮件原件-----
发件人: itu-sg16-bounces@lists.packetizer.com
[mailto:itu-sg16-bounces@lists.packetizer.com] 代表 Paul E. Jones
发送时间: 2008年9月11日 10:48
收件人: 'zourong 52447'
抄送: itu-sg16@lists.packetizer.com
主题: Re: [itu-sg16] Q22 Question - SATC
Rong,
I think the meeting report is not exactly correct.  The Q22
meeting> > > report
...
...
...
said that SATC would block content that that failed to match a
signature.
What you said is that SATC would block media content that
matches a
...
"good"
signature, but is apparently altered in some way.  That is, it
would
...
...
block
media that it can clearly identify as pirated content.
So, perhaps we should revise the wording that is presently in
the Q22
...
meeting report related to AVD-3541.  Can you consult Noah on
what the
...
correct statement should be?
As for whether this will work, I still have doubts.  Even
storing> > > signatures
...
...
...
of all current media could be a massive database and, quite
likely, one
...
that
would need to be in memory, as you need real-time (and likely
wire-
...
speed)
access to the signatures.
I have no objection to doing work on this: if you can meet a
particular> business requirement, great.  But, I personally think
that trying to
...
match
against signatures will not stop any serious pirate.  It might
stop the
...
casual pirate, though.
A data stream of pirated content can be altered in so many ways
that it
...
would be easy for somebody to create a program to stream pirated
content
that does not match a signature in the database.  I could run
the media
...
stream through a cipher algorithm, for example.  And, I
could even
...
...
...
transmit
the cipher key as the last payload of the message: after
all, the
...
...
...
entire
file has been delivered!  Secrecy wasn't the purpose of the
encryption,> but
...
merely to disguise what is being transmitted until we've
successfully> bypassed the SATC "detectors".
...
Perhaps the simplest thing to do, actually, given the wide
proliferation of
tools like OpenSSL, is to just use TLS between nodes that
want to
...
...
...
transmit
pirated content.  That provide more-than-acceptable level of
encryption.
In any case, I did not intend to bring the work to a halt,
by any
...
...
...
means.
But, be cognizant of the fact that this is a very complex
problem and I
...
seriously doubt you can devise a method that would prevent a
good> > > hacker
...
...
...
from getting around the system.  At best, you will only stop the
casual> "pirates".  You would not stop serious pirates or popular
"file> sharing"
...
software.  Such software would definitely employ techniques
to get
...
...
...
around
any detection/blocking logic in the router/switch.
What's more important right now is understanding what should
have been
...
stated in the meeting report.  I do not think this sentence is
accurate:
“... if SATC finds a data stream carrying content failing to
match a
...
known
signature, it will block the stream or mark it as being
suspicious.”
...
...
Paul
...
-----Original Message-----
From: zourong 52447 [mailto:zou.rong@huawei.com]
Sent: Wednesday, September 10, 2008 4:05 AM
To: paulej@packetizer.com
Cc: itu-sg16@lists.packetizer.com
Subject: [itu-sg16] Q22 Question - SATC
Paul,
really thanks your's comments, here is the clarification.

As to the circumventing problem, I really could not say

their is
...
...
a perfect way that could not be circumvented. But I don’t
think it is
...
...
easy to do so. This scenario is attempted to provide a
tool for
...
...
...
content
...
provider to prevent their “specially processed” content, i.e.
copy-
...
...
righted content from being pirated. It is assumed the
“specially> > > > processed” content have some characteristic 
information that
...
...
would be
...
...
destroyed by any piratical actio
n such as using a different decoding method, and these
characteristic> > information or “signature” would be provided to
SATC system by
...
content
...
provider. As to the compress scheme to circumvent, I think the
SATC> > could handle most of the common compress schemes such as
winzar,> > winzip, tar etc., but I also think it is impossible the
SATC could
...
...
handle all compress schemes.
2)	The method mentioned in AVD-3541 is not attempted to create
a
...
...
...
database of all  pirated media, it’s a database that store the
signature of good media especially those most popular
video or
...
...
audio> > recently, so the database will keep in a state of
acceptable size.
...
The
...
periodical updating of the database is necessary just like the
IDS do
...
...
to update the anti-virus database.
3)	The pirated media database could exist as an subsidiary
database.> > This was not mentioned in the AVD-3541 because I
think it maybe too
...
...
detail to describe it in a scenario. The file transmitted
will be
...
...
...
...
suspected as pirated file when satisfied following two points:
(1)
...
...
...
There is a item in the “good media database” that means the
file is a
...
...
target of protecting. (2)the signature of the file transmitted
do not
...
...
match with that stored in the data
base. Then the suspected file could be blocked directly,
or in
...
...
a more
...
...
prudent way, it could be just marked as suspicious and search
in a
...
...
subsidiary “pirated media database” to make sure it is a
existing> > > > pirated version or it maybe a new pirated version 
and need more
...
...
...
manual
...
analytical works of content provider.
4)	As to the performance problem, I think this kind of
inspection
...
...
...
may have some negative impact on the packet transmission but
may not
...
as
...
terrible as thought, in fact, many DPI product in market can
achieve> > 10G to 40G, even 80G throughput, their process
capability is
...
...
remarkable.
...
发件人： Paul E. Jones
发送时间： 2008-09-05 10:59:38
收件人： itu-sg16@lists.packetizer.com
抄送：
主题： [itu-sg16] Q22 Question - SATC
Q22 Experts,
While reviewing the Q22 meeting report, I was intrigued
by a
...
...
...
...
...
comment related to AVD-3541.  This contribution proposes
that SATC
...
...
...
can be used to block illegal content from being transmitted
over
...
...
...
...
the Internet by examining the media flow and comparing that
media> > > flow (or some signature thereof) against a database.
SATC would
...
...
...
then block content as appropriate.
I would like to comment:

 I could easily circumvent any such measure, so 

any such
...
...
...
...
...
system would prove to work only temporarily; and
2)      While a given copy of a digital copy of some
content, such
...
...
...
as music or a movie, will have a clearly recognizable
signature,
...
...
...
...
the same media can be “substantially” altered by merely
using a
...
...
...
different encoding method (e.g., a different video codec or
compression scheme); and
3)      Actually attempting to create a database of all
known> > > > > pirated media, including all variations, would 
result in the
...
...
...
...
...
creation of a massively huge database; and
4)      Maintenance of such a database would be a never-
ending> > > > > chore; and
...
...
...
...
...

 Notwithstanding the foregoing, while such a database

could> > > be constructed and flows could be examined, inspecting
flows in
...
...
...
real-time and trying to positively identify a given flow
is a
...
...
...
...
...
monumental task that will result in significantly negative
impact> > > on packet transmission performance, even if a bank of
specialized> > > network processors were employed per router or
switch
...
...
...
...
In short: do we really want to attempt this?  While it’s all
technically possible (at the risk of turning a 1Gbps pipe
into a
...
...
...
1Kbps pipe), I would argue that it’s not going to work.  I
would
...
...
...
...
be happy to be first in line to write the software
necessary to
...
...
...
...
...
circumvent such a system.  And I would do it just
because I
...
...
can ;-)
...
...
...
Having said that, the meeting report said that, the meeting
report> > > said that “if SATC finds a data stream carrying
content failing to
...
...
...
match a known signature, it will block the stream or
mark it as
...
...
...
...
...
being suspicious.”
I underlined the text of significance.  This suggests
that the
...
...
...
...
...
database would only be populated with signatures of
known good
...
...
...
...
...
media flows and would only block unrecognized flows.  This
seems
...
...
...
...
different than what I read and understood from AVD-3541.
What the
...
...
...
meeting report suggests would be a simpler problem with a
substantially smaller database.  So, what was actually
discussed
...
...
...
...
and decided for SATC?  A system that blocks unrecognized
flows or
...
...
...
a system that blocks recognized flows?
Thanks,
Paul

回复:RE: RE: [itu-sg16] Q22 Question - SATC

zourong 52447

tags (0)

participants (1)