Not a single intelligence agency or diplomatic service will rely on ToR for security that’s madness.

A properly configured commercial or open source VPN is considerably more reliable and secure than ToR since you have no idea who is listening on the exit nodes or who can execute unmasking attacks by traffic shaping or monitoring if they control enough relays.

For the most part any country which can perform intelligence collection out of its embassy will have sufficient budget and and technical capacity to develop their own secure means of phoning home.

Also for highly sensitive material a diplomatic pouch is still the most secure means of transport as it never leaves your sight and is never inspected and if you do get intercepted then destroying physical media is much easier than securing network traffic to the same level of assurance.

>Not a single intelligence agency or diplomatic service will rely on ToR for security that’s madness... For the most part any country which can perform intelligence collection out of its embassy will have sufficient budget and and technical capacity to develop their own secure means of phoning home.

The CIA has it's own onion service: ciadotgov4sjwlzihbbgxnqg3xiyrg7so2r2o3lt5wz5ypk4sxyjstad.onion

Tor was developed by the US naval research lab, it was opened up because an anonymity network only spooks use isn't anonymous.

Smart intelligence agencies are not going to reinvent the wheel (or in this case, the onion router).

>A properly configured commercial or open source VPN is considerably more reliable and secure than ToR since you have no idea who is listening on the exit nodes

If traffic is encrypted this does not matter. (HTTPS also provides integrity checking to show messages were not modified in transit)

Also, traffic to onion services does not exit the Tor network - there is no "exit node"

>Also for highly sensitive material a diplomatic pouch is still the most secure means of transport as it never leaves your sight and is never inspected and if you do get intercepted then destroying physical media is much easier than securing network traffic to the same level of assurance.

They may use diplomatic pouches for especially sensitive information, but the need for low latency communication is strong. What's more likely is that one time pad codes for said communications are sent via pouch, and the communication itself then goes over Tor or some other channel.

Why would embassies need to be anonymous?

If I needed to design a secure system that didn't need to be anonymous I'd just have it send a HD full of random in a diplomatic pouch & ensure that the packets are sent with encrypted 0s if there isn't anything to say.

And that's only if you think that there isn't a safe pubic key protocol.

Bitcoin's security model relies on public key encryption & there is an extremely large bounty on breaking it. There doesn't seem to be evidence of it being broken yet.

Wow I wonder how much compute it took them to generate that hidden service name.

I tried one of the older, shorter .onion addresses once out of interest. Didn't take long on a laptop to get a specified 7 characters at the beginning.

I don't know how much the longer .onions affects generation time - anyone?

Is there a script to do that or did you roll your own?

I used https://github.com/katmagic/Shallot back then and it took 35221958203 attempts to find one with my chosen seven characters.

For the longer v3 .onions you'll want a different tool, this page mentions some and makes some estimates for finding increasing lengths of characters: https://www.jamieweb.net/blog/onionv3-vanity-address/

HTTPS with SNI leaks what one visits, and if an adversary controls enough of the network they could also use timing attacks.

Yes but why would you use a single hop VPN instead of Tor? Wouldn't both leak that?

(Also it's my understanding Tor uses the exit node's DNS server)

Unless they communicate via a hidden service, in which case there is no exit node, so that particular problem is easy to avoid.

Tor is an anonymizer. Why would embassies use an anonymizer for communicating back home? Everyone knows they’ll be communicating with home. There’s no point in hiding that. What you want to hide is the content of that communication, which Tor doesn’t do very well. You do that with standard encryption tools.

Because if you don't know where traffic is going or coming from it's harder to infer what the message is about.

It’s not hard to infer that traffic from an embassy is probably going to their home country.

You properly encrypt it and regularly send data (like in a VPN). Done.

So you're claiming that using a VPN makes correlation attacks impossible? Do you have any sources on this? I'd love to read up to better understand your thinking.

Correlation attacks are attacing anonymity. If you are an embassy, there is no need for anonymity. Ok, an embassy connected to vpn.whitehouse.gov and sent 20 gb of data, so what?

(unless you are thinking about high level things, like "lots of traffic" -> "something going on", but tor won't help with that either)

I feel like if I were a network operator for something that sensitive I might send some bursts of traffic to nothing just to keep anyone trying to infer "lots of traffic" → "something going on" on their toes.

(Though certainly things like packet timing, packet size, etc. might make more thorough analyses harder to escape…)

I'm now imagining a significant portion of some small country in politically sensitive area's external internet bandwidth being composed entirely of vpn encrypted email with attached Word docs and Powerpoint decks full of "This page left intentionally blank" sent from embassies back to their respective motherships...

A highly secure connection either uses a fixed-bandwidth pipe or constantly sends random data to avoid correlation like this.

>unless you are thinking about high level things, like "lots of traffic" -> "something going on", but tor won't help with that either

But is an embassy always only "phoning home"?

Yes, it's good practice for an embassy to use a VPN to their home country for 100% of incoming and outgoing traffic (at least that's how I would do it).

Yes, if you are an embassy, you can be pretty sure that the host country is watching all of your traffic very carefully. Having all the traffic go via VPN is just sanity.

(and for really secure stuff you will want a channel with constant rate, constant size packets, as others said)

One time pads[1] are an effective and cheap measure. Certain privileged diplomatic luggage (not exactly sure of the protocols) cannot be searched by the host country. You can bring them to your embassies on a regular basis.

1 -https://en.wikipedia.org/wiki/One-time_pad

Or just set up an OTP then use the OTP to send new OTPs securely, boom.

If you do this, it is no longer OTP.

I think it still is:

1. Alice and Bob set up their OTP

2. Alice randomly generates a new OTP

3. Alice encrypts the new OTP with the original OTP and sends the ciphertext to Bob

4. Bob decrypts... the new OTP

5. Alice and Bob burn the original OTP

6. Now Alice and Bob have a copy of the new OTP

I mean, it's pointless. But I don't see how it isn't secure.

For those who do not know exactly how OTP works:

jancsika is right in the sense that this is possible, but meaningless. The reason for that is that in OTP, you use your key ("pad") for every transmission, in 1-to-1 ratio to amount of data being transmitted. And you can only use your key once (hence "one time pad")

So let's say you brought 1000 MB of OTP keys to embassy in diplomatic mail, you can use it to send up to 1000 MB of encrypted data, and then you have to get a new one. If you are low on OTP keys, and you use it to send a new one, you'll have to spend 100 MB of "old" OTP keys to get 100 MB of "new" OTP keys -- entirely pointless process, as amount of unused key data won't change.

On the other hand, if Alice and Bob are just constantly sending each other these messages as a pointless exercise, the traffic they generate by doing so would technically make the exercise rise above the level of pointlessness. :)

Dedicated fibre, terrestrial radio, commercial and military satellite links. [0] Crypto algorithms implemented in hardware, keys managed by the signals intelligence agency.

The Department of Defense is probably one the largest and most sophisticated telecoms in the world. Cannot have dependencies on local infrastructure in countries you are bombing.

[0] https://en.wikipedia.org/wiki/Defense_Information_System_Net...

I'd be surprised if the big countries used plain Tor for their vital communication. They would be having their own secret networks or tunnel through Tor. Small countries have probably simply given up hiding their intelligence from the big ones at this point and are simply interested in ensuring their immediate rivals are kept out, which Tor can probably do.

A custom protocol can potentially be fingerprinted. I wouldn't be surprised if they used something less sophisticated. Like (encrypted) direct messages on twitter/reddit/facebook. This way the traffic blends with the rest.

There's a companion project to Tor called obs4proxy which is designed to hide the protocol's implementation.

It doesn't need to be a completely custom protocol. HTTPS can handle a very large percentage of anyone's communication needs these days.

An application level protocol implemented on top of HTTPS can be fingerprinted. If you look up "Website Traffic Fingerprinting" you will see what I mean. That traffic is encrypted.

For official operations, they would not be using the internet in any way, but their own parallel enterprise networks. Tor could be useful for covert operatives, and for generally weakening the grip of governments where we are inducing "popular" uprisings.

The fact that the embassy talks to the mothership is not secret.

How much it does so might be, and what it talks certainly is, but that's easily fixed by getting a line with dedicated bandwidth, running an encrypted connection (VPN or something custom) over it, and padding the traffic to ensure the bandwidth usage is constant (if you have a 100 Mbit line and 10 Mbit of traffic, you send 90 Mbit of padding).

The keys for the VPN get delivered via diplomatic courier.

Why do they need anything more than HTTPS? Just open https://nsa.gov/ and send your data.

Because that reveals that you are talking to the NSA right now. Sometimes the volume of chatter is useful information in its own right. Sure, you could script something to make the data rate constant, but that might be undesirably expensive and if you do everything over Tor then your video chat with HQ looks indistinguishable from you bit torrenting pirate episodes of My Little Pony.

I can't currently find the place on Wikipedia where I learned this, but an example of "volume of chatter" being important was e.g. before the attack on pearl harbor. While the US couldn't decrypt the internal messages, it was clear that an attack was imminent based on the pattern (including the radio silence) before the attack.