[tor-dev] Is it possible to leak huge load of data over onions?

2016-04-03 Thread grarpamp 
On 4/3/16, Griffin Boyce  wrote:
> How do you transmit an elephant? One byte at a time...
>
> But on a serious note, it's possible to transfer 2.6TB over Tor in small
> pieces (such as file by file or via torrent). Given the size, however, I'd
> suspect they mailed hard drives after establishing contact with
> journalists. Even on a fairly fast connection, 2.6TB would take quite a
> while...

That amount of data would take 27 days at 10Mbps.
Few would be willing to sit supervising in a hotseat that long
when they can physically mail 3TB for $100 and 8TB for $230.
Though they might spend 3 days pushing 100Mbps via shells, etc.
Overlay networks move data reasonably well, and reliability
could be handled by chunking protocols. Available link
speeds (thus path speeds) are likely to be limiting factor,
ie: 10Mbps limits you to 100GiB a day. Though at 1Mbps,
DVD torrenting on say I2P seems to be a thing.
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Re: [tor-dev] Is it possible to leak huge load of data over onions?

2016-04-03 Thread Ivan Markin 
NB: Sorry for breaking the threading. Replying to the right message.

dawuud:

> Alice and Bob can share lots of files and they can do so with their
> Tor onion services. They should be able to exchange files without
> requiring them to be online at the same time. Are you sure you've
> choosen the right model for file sharing?

I haven't chosen any storage model. I'm just wondering about technical
capabilities of Tor to act as _anonymous_ transport for this data.
"Will one be anonymous when they transmit big amount of data?"
"What the limits are?"
"What step should the source take to be safe?"

> If Alice and Bob share a confidential, authenticated communications
> channel then they can use that to exchange key material and secret
> connection information. That should be enough to bootstrap the
> exchange of large amounts of documents:

The Internet is not confidential. Surely the opposite.

> Anyone who hacks the storage servers she is operating gets to see
> some interesting and useful metadata such as the size of the files
> and what time they are read; not nearly as bad as a total loss in
> confidentiality.

Yes, but there are much more adversaries. Any AS near the endpoints
poses big threat.

> No that's not necessarily correct; if the drives contain ciphertext
> and the key was not compromised then the situation would not be
> risky.

The source can easily fail by compromising fingerprints, chemical
traces, serial number of the hard drive (with proprietary firmware!),
place of origin and other 'physical' metadata. It's not "just
ciphertext" in a vacuum.

--
Ivan Markin
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Re: [tor-dev] Is it possible to leak huge load of data over onions?

2016-04-03 Thread Peter Tonoli 

On 4/04/2016 10:31 AM, Griffin Boyce wrote:


How do you transmit an elephant? One byte at a time...

rsync is a beautiful thing. Have different clients / nodes accessing 
separate file paths. If the transfer drops out / is too slow, start up 
rsync again..


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Re: [tor-dev] Is it possible to leak huge load of data over onions?

2016-04-03 Thread dawuud 

Hi.

My general feeling here is that it's more useful for me to tell you how I think
people should share files than it would be for me to answer your questions; 
sorry, not sorry.

Alice and Bob can share lots of files and they can do so with their Tor onion 
services.
They should be able to exchange files without requiring them to be online at 
the same time.
Are you sure you've choosen the right model for file sharing?

If you want reliability then you should desire to not have single points of 
failure
such as a single Tor circuit or a single onion service; further, the high 
availability
property might be important for certain types of file sharing situations.

If Alice and Bob share a confidential, authenticated communications channel then
they can use that to exchange key material and secret connection information.
That should be enough to bootstrap the exchange of large amounts of documents:

- Alice is clueful about distributed content-addressable ciphertext storage so 
she
decides to operate a Tahoe-LAFS storage grid over onion services.
- Alice uploads her ciphertext to the tahoe grid.
- Alice sends Bob the secret grid connection information and cryptographic 
capability to read her files.

In this situation Alice really doesn't care where her storage nodes are hosted 
and if the virtual
server hosting provider can be depended on to not get hacked or receive a 
national security letter.
Why does Alice give zero fucks? ciphertext. "They" have her ciphertext and it's 
useless without a key compromise.
Anyone who hacks the storage servers she is operating gets to see some 
interesting and useful metadata
such as the size of the files and what time they are read; not nearly as bad as 
a total loss in confidentiality.

https://gnunet.org/sites/default/files/lafs.pdf

However what if Alice decides that Bob is a useless human being and she should 
instead
publicize the documents herself? She writes her own badass adversary resistent
distributed ciphertext storage system and convinces several organizations world 
wide
to operate storage servers in various countries and thus several legal 
jurisdictions.

She can now gleefully upload ciphertext via onions services to the storage 
servers and
then simply publicize the key material for specific files she wishes to share 
with the world
or an individual. She can make this system censorship resistant by utilizing an 
erasure encoding
for storing the ciphertext. For instance Tahoe-LAFS uses Reed Solomon encoding 
such that any K of N
shares can be used to construct the ciphertext of the file. In this case if an 
adversary wanted to
censor Alice's ciphertext publication they would have to DOS-attack N-K+1 
servers.

> Recently someone leaked enormous amount of docs (2.6 TiB) to the
> journalists [1]. It's still hard to do such thing even over plain old
> Internet. Highly possible that these docs were transfered on a physical
> hard drive despite doing so is really *risky*.

No that's not necessarily correct; if the drives contain ciphertext and
the key was not compromised then the situation would not be risky.


> Anyways, in the framework of anonymous whistleblowing, i.e. SecureDrop
> and Tor specifically it's seems to be an interesting case. I'm wondering
> about the following aspects:
> 
> o   Even if we use exit mode/non-anonymous onions (RSOS)
> is such leaking reliable? The primary issue here
> is time of transmission. It's much longer than any
> time period we have in Tor.
> 
> o   What is going to happen with the connection after
> the HS republishes its descriptor? Long after?
> [This one is probably fine if we are not using
>  IPs, but...]
> 
> o Most importantly, is transferring data on >1 TiB
> scale (or just transferring data for days) safe at
> all? At least the source should not change their
> location/RP/circuits. Or need to pack all this stuff
> into chunks and send them separately. It's not
> obvious how it can be done properly. So at what
> point the source should stop the transmission
> (size/time/etc)/change location or the guard/
> pick new RP?
> 
> --
> [1] http://panamapapers.sueddeutsche.de/articles/56febff0a1bb8d3c3495adf4/
> --
> Happy hacking,
> Ivan Markin
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> tor-dev mailing list
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[tor-dev] Is it possible to leak huge load of data over onions?

2016-04-03 Thread Ivan Markin 
Recently someone leaked enormous amount of docs (2.6 TiB) to the
journalists [1]. It's still hard to do such thing even over plain old
Internet. Highly possible that these docs were transfered on a physical
hard drive despite doing so is really *risky*.

Anyways, in the framework of anonymous whistleblowing, i.e. SecureDrop
and Tor specifically it's seems to be an interesting case. I'm wondering
about the following aspects:

o   Even if we use exit mode/non-anonymous onions (RSOS)
is such leaking reliable? The primary issue here
is time of transmission. It's much longer than any
time period we have in Tor.

o   What is going to happen with the connection after
the HS republishes its descriptor? Long after?
[This one is probably fine if we are not using
 IPs, but...]

o   Most importantly, is transferring data on >1 TiB
scale (or just transferring data for days) safe at
all? At least the source should not change their
location/RP/circuits. Or need to pack all this stuff
into chunks and send them separately. It's not
obvious how it can be done properly. So at what
point the source should stop the transmission
(size/time/etc)/change location or the guard/
pick new RP?

--
[1] http://panamapapers.sueddeutsche.de/articles/56febff0a1bb8d3c3495adf4/
--
Happy hacking,
Ivan Markin
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Re: [tor-dev] Is it possible to leak huge load of data over onions?

2016-04-03 Thread Griffin Boyce 

How do you transmit an elephant? One byte at a time...

But on a serious note, it's possible to transfer 2.6TB over Tor in small 
pieces (such as file by file or via torrent). Given the size, however, I'd 
suspect they mailed hard drives after establishing contact with 
journalists. Even on a fairly fast connection, 2.6TB would take quite a 
while...


~Griffin



--
On Sun, Apr 03, 2016 at 5:24 PM, Ivan Markin < t...@riseup.net 
[t...@riseup.net] > wrote:

Recently someone leaked enormous amount of docs (2.6 TiB) to the
journalists [1]. It's still hard to do such thing even over plain old
Internet. Highly possible that these docs were transfered on a physical
hard drive despite doing so is really *risky*.

Anyways, in the framework of anonymous whistleblowing, i.e. SecureDrop
and Tor specifically it's seems to be an interesting case. I'm wondering
about the following aspects:

o Even if we use exit mode/non-anonymous onions (RSOS)
is such leaking reliable? The primary issue here
is time of transmission. It's much longer than any
time period we have in Tor.

o What is going to happen with the connection after
the HS republishes its descriptor? Long after?
[This one is probably fine if we are not using
IPs, but...]

o Most importantly, is transferring data on >1 TiB
scale (or just transferring data for days) safe at
all? At least the source should not change their
location/RP/circuits. Or need to pack all this stuff
into chunks and send them separately. It's not
obvious how it can be done properly. So at what
point the source should stop the transmission
(size/time/etc)/change location or the guard/
pick new RP?

--
[1] http://panamapapers.sueddeutsche.de/articles/56febff0a1bb8d3c3495adf4/
--
Happy hacking,
Ivan Markin
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[tor-dev] Is it possible to leak huge load of data over onions?

2016-04-03 Thread Ivan Markin 
Recently someone leaked enormous amount of docs (2.6 TiB) to the
journalists [1]. It's still hard to do such thing even over plain old
Internet. Highly possible that these docs were transfered on a physical
hard drive despite doing so is really *risky*.

Anyways, in the framework of anonymous whistleblowing, i.e. SecureDrop
and Tor specifically it's seems to be an interesting case. I'm wondering
about the following aspects:

o   Even if we use exit mode/non-anonymous onions (RSOS)
is such leaking reliable? The primary issue here
is time of transmission. It's much longer than any
time period we have in Tor.

o   What is going to happen with the connection after
the HS republishes its descriptor? Long after?
[This one is probably fine if we are not using
 IPs, but...]

o   Most importantly, is transferring data on >1 TiB
scale (or just transferring data for days) safe at
all? At least the source should not change their
location/RP/circuits. Or need to pack all this stuff
into chunks and send them separately. It's not
obvious how it can be done properly. So at what
point the source should stop the transmission
(size/time/etc)/change location or the guard/
pick new RP?

--
[1] http://panamapapers.sueddeutsche.de/articles/56febff0a1bb8d3c3495adf4/
--
Happy hacking,
Ivan Markin
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