Of course they know which client connects when to their server and sends messages to them. Seal sender is only about cutting the direct relation between that sending event and the receiver. However they also know exactly when a client receives a message (just not directly from whom). Thus since they know exactly when clients send and receive messages it is trivial to run a timing attack for a few minutes and you know with 99.9% certainty who is talking to whom, even with seal sender.
If that were the case, the sealed sender stuff would a complete lie, which would seem out of character for Signal.
Of course they know which client connects when to their server and sends messages to them.
Why ? The authentication can be done on the receiving side through cryptography. Why would it be required for the server to also authenticate the sender?
If that were the case, the sealed sender stuff would a complete lie, which would seem out of character for Signal.
It seems like your loyalty to signal isn’t based on any facts or history whatsoever. I go over the untrustworthy history of signal’s founders, but you’ve ignored all those points in your replies so far.
I go over the untrustworthy history of signal’s founders
The OTF also funds the following:
Briar, Tor, Wireguard, Delta Chat, Bind9, CGIProxy, CertBot, K-9 Mail, Tails, NoScript, QubesOS, The Guardian Project
You going to say that Briar is a good alternative despite receiving funding from the CIA just like Signal? How about QubesOS or NoScript. Are they also no longer trustworthy because they’re funded by the OTF?
That honestly does make me question those projects a bit more, and should put some more scrutiny on them. Radio free asia is not looking out for open source, they’re trying to get a jump on coopting projects, because no one else is funding open source.
I go over the untrustworthy history of signal’s founders, but you’ve ignored all those points in your replies so far.
Regarding your radio free asia funding story, Whisper Systems was founded in 2010 according to Wikipedia, while the funding from the open tech fund started in 2013.
There’s a lot of differences between Funding and FOunding. At that point it was already open sourced. It’s really far fetched to think that somehow, the US took control of it at that point.
You even ignore the point that Whisper System temporarily belonged to twitter, also a US company, which would have been a much simpler way for the US to seize control of the project than to go through some fund bla bla bla
Of course, I never said it was founded by radio free asia, just that it got its initial funding from them. The only thing thats up for debate there, is their continued involvement.
But based on them defending signal from critics as recently as a few years ago.
2ndly, open source doesn’t mean too much for centralized services that aren’t self hostable, and especially ones that delay their source code updates until the community wonders why there haven’t been any after a full year.
Whisper Systems was founded in 2010 according to Wikipedia, while the funding from the open tech fund started in 2013.
Interestingly, Singnal actually introduced its cryptographic protocol to the public only in 2013, when they got the funding (see even Wikipedia for that).
The app already had E2EE at that point, this only marks the release of the v2 of their protocol, which is now considered state of the art for asynchronous messaging.
Its not a complete lie, as a similar system on a federated messenger where lots of different legal entities control the different client to server connections would really benefit from it (I hope someone will implement it for XMPP in the future), but due to the centralization of the Signal servers it is snake-oil as explained above.
I am not sure what you mean with “authenticate” in this context, but of course the signal servers receive TCP connection from a specific IP address at a specific point in time. If they also look at that TCP connection and authenticate the sender is mostly irrelevant, but I would guess they also do that to prevent network spam / flooding attacks.
Edit: I think a lot of the things Signal does are good so long as you trust them and assume not a single one of their employees (or one of those their servers run on, AFAIK previously Google and now AWS) is compromised by the NSA/FBI. I find that highly unlikely and thus have to assume Signal’s servers are run by a hostile actor and according to that such timing attacks are likely to happen.
If the only thing they have is an IP address it is much less info than the actual phone number of who sent the message. It can also be very easily prevented by using a VPN or the built-in anti censorship proxy.
If you use additional measures to protect yourself it becomes a bit more difficult to correlate the info, but they still also know when a specific client with a specific phone number connects to their network. So maybe they have to run that timing attack over a few hours, but the end result is the same.
they still also know when a specific client with a specific phone number connects to their network
I don’t think so. I didn’t really fully understood how sealed sender worked until now and only trusted Signal to implement it properly. I’m currently reading this which explains how it works and it seems to provide similar guaranties to what I assumed.
The server can only have the IP of the sender. There seem to be some issues, but it’s not as trivial as you seem to think it is. They may also have implemented the mitigations since.
How do they know when a specific client sends a message?
Because that client connects to their server to do so roll eyes
And how do they identify this client specifically instead of any other client?
Of course they know which client connects when to their server and sends messages to them. Seal sender is only about cutting the direct relation between that sending event and the receiver. However they also know exactly when a client receives a message (just not directly from whom). Thus since they know exactly when clients send and receive messages it is trivial to run a timing attack for a few minutes and you know with 99.9% certainty who is talking to whom, even with seal sender.
If that were the case, the sealed sender stuff would a complete lie, which would seem out of character for Signal.
Why ? The authentication can be done on the receiving side through cryptography. Why would it be required for the server to also authenticate the sender?
It seems like your loyalty to signal isn’t based on any facts or history whatsoever. I go over the untrustworthy history of signal’s founders, but you’ve ignored all those points in your replies so far.
The OTF also funds the following: Briar, Tor, Wireguard, Delta Chat, Bind9, CGIProxy, CertBot, K-9 Mail, Tails, NoScript, QubesOS, The Guardian Project
You going to say that Briar is a good alternative despite receiving funding from the CIA just like Signal? How about QubesOS or NoScript. Are they also no longer trustworthy because they’re funded by the OTF?
That honestly does make me question those projects a bit more, and should put some more scrutiny on them. Radio free asia is not looking out for open source, they’re trying to get a jump on coopting projects, because no one else is funding open source.
See this comment
Regarding your radio free asia funding story, Whisper Systems was founded in 2010 according to Wikipedia, while the funding from the open tech fund started in 2013. There’s a lot of differences between Funding and FOunding. At that point it was already open sourced. It’s really far fetched to think that somehow, the US took control of it at that point.
You even ignore the point that Whisper System temporarily belonged to twitter, also a US company, which would have been a much simpler way for the US to seize control of the project than to go through some fund bla bla bla
Of course, I never said it was founded by radio free asia, just that it got its initial funding from them. The only thing thats up for debate there, is their continued involvement.
But based on them defending signal from critics as recently as a few years ago.
2ndly, open source doesn’t mean too much for centralized services that aren’t self hostable, and especially ones that delay their source code updates until the community wonders why there haven’t been any after a full year.
In this comment you say founded. I can accept that it’s a typo.
Link?
There are forks that exists such as Session. Open Source is important
Interestingly, Singnal actually introduced its cryptographic protocol to the public only in 2013, when they got the funding (see even Wikipedia for that).
The app already had E2EE at that point, this only marks the release of the v2 of their protocol, which is now considered state of the art for asynchronous messaging.
Its not a complete lie, as a similar system on a federated messenger where lots of different legal entities control the different client to server connections would really benefit from it (I hope someone will implement it for XMPP in the future), but due to the centralization of the Signal servers it is snake-oil as explained above.
I am not sure what you mean with “authenticate” in this context, but of course the signal servers receive TCP connection from a specific IP address at a specific point in time. If they also look at that TCP connection and authenticate the sender is mostly irrelevant, but I would guess they also do that to prevent network spam / flooding attacks.
Edit: I think a lot of the things Signal does are good so long as you trust them and assume not a single one of their employees (or one of those their servers run on, AFAIK previously Google and now AWS) is compromised by the NSA/FBI. I find that highly unlikely and thus have to assume Signal’s servers are run by a hostile actor and according to that such timing attacks are likely to happen.
If the only thing they have is an IP address it is much less info than the actual phone number of who sent the message. It can also be very easily prevented by using a VPN or the built-in anti censorship proxy.
If you use additional measures to protect yourself it becomes a bit more difficult to correlate the info, but they still also know when a specific client with a specific phone number connects to their network. So maybe they have to run that timing attack over a few hours, but the end result is the same.
Not to point out the obvious, but if someone uses a burner phone to initially setup their signal account, that is another big layer of privacy
I don’t think so. I didn’t really fully understood how sealed sender worked until now and only trusted Signal to implement it properly. I’m currently reading this which explains how it works and it seems to provide similar guaranties to what I assumed. The server can only have the IP of the sender. There seem to be some issues, but it’s not as trivial as you seem to think it is. They may also have implemented the mitigations since.