3 ms·

Why would you need proof that it has been backdoored? The fact that it can be backdoored should be enough to disregard it for all uses right from the start.

fragmede 3y ago
Trusting Trust says everything could be backdoored, but somehow I'm guessing you still use computers.
- GuB-42 3y ago
  We use computers because it is pretty much impossible to live in modern society without using computers. But by the time Dual_EC_DRBG was published, we already had alternatives that were better in just about every way, including being much less likely to contain a backdoor.
- suprfsat 3y ago
  We should improve society somewhat.
- jiggawatts 3y ago
  If, for example, SHA2 had a backdoor or a weakness known only to the NSA, then random contractors (like Snowden) could use that to extract money from the Bitcoin network, which uses SHA256 as its core cryptographic primitive. That's easily a billion dollar motivation right there, and I can't imagine a bunch of low-paid government drones resisting that cash prize. Everyone has a price. Hence, there's a level of trust that can be gained through observation of failures to abuse backdoors. If they don't exist, they can't be abused. If they exist, then they must be used/abused, otherwise what's the point? Such usage will be eventually discovered. E.g.: The use of the Dual_EC_DRBG back-door to tap into Juniper VPN connections by the Chinese government was discovered and made public.
  - leetbulb 3y ago
    I'm not advocating in either direction here, but let's assume backdoors like this do exist: Just because they haven't been abused doesn't mean that they wont in the future. Of the people I know that work with highly privileged materials, none would take advantage or abuse something like this, even with such a high payout. Even if they did, how would they continue to live comfortably? That said, it just takes one person under the right circumstances to act maliciously, which is why screening and compartmentalization is critically important for these organizations.
    - jiggawatts 3y ago
      The SHA2 standard is now 22 years old. That's an awfully long wait to start utilising a back door!
- dllthomas 3y ago
  Interestingly, Trusting Trust style attacks on compilers was later (theoretically, idk to what degree it's been put into practice) solved by "diverse double compiling": https://dwheeler.com/trusting-trust/ https://dwheeler.com/trusting-trust/
jiggawatts 3y ago
There are some algorithms where there's no obvious way to back door it, but it's always conceivable -- the person designing it may know some clever mathematics that you don't. With Dual_EC_DRBG, everyone knew that it could be back doored. It's not some guess, or "maybe it could have". It was obviously designed to be back doored. It should have been called "NSA_BACKDOOR_RNG", because that's literally what it is. And yes, all organisations that are not under the thumb of the US Government laughed at the transparent attempt to introduce a back door and rejected Dual_EC_DRBG. Only US-based companies use it, which ought to give you a hint.
thephyber 3y ago
The “need” for proof here determines whether there was likely malicious intent or negligence/ignorance. People who live in an evidence-based rational world don’t skip the evidence step and go straight to possibilities and counterfactuals.
- samplatt 3y ago
  There's a certain point in the security world where paranoia becomes a requirement, even though it only breeds more paranoia. An outcome of this is the requirement to treat all possibilities as certainties, regardless of evidence. In this way, entire sections of industry will auto-assume the backdoor was both deliberate, and used both both friendlies & hostiles.
  - AnthonyMouse 3y ago
    Knowledge that this environment exists is also strong evidence that it was a backdoor. If you propose a clearly questionable security practice in some arbitrary bureaucracy, the assumption is it's incompetence because that happens all the time and no one detects it until it's already in production. If you propose a clearly questionable security practice to a cryptography standards body, the expectation is that you get laughed out of the room. Even the possibility of a backdoor would make everyone skeptical, which would be useless in a standard because no one would trust it. And yet it made it through the standards process for some reason, but there is only one plausible reason.
  - thephyber 3y ago
    > In this way, entire sections of industry will auto-assume the backdoor was both deliberate, and used both both friendlies & hostiles. That’s fine. But they should be equally paranoid of all substitute products/services that use other recommendations from NIST, right? Are there greater than zero products on the (US) market with no encryption in the system recommended by NIST? Also, I don’t think I was limiting my thinking to a customer of the weak encryption product. I was also thinking through the lens of legal implications.
- jacquesm 3y ago

fragmede 3y ago

Trusting Trust says everything could be backdoored, but somehow I'm guessing you still use computers.

GuB-42 3y ago
We use computers because it is pretty much impossible to live in modern society without using computers. But by the time Dual_EC_DRBG was published, we already had alternatives that were better in just about every way, including being much less likely to contain a backdoor.
suprfsat 3y ago
We should improve society somewhat.
jiggawatts 3y ago
If, for example, SHA2 had a backdoor or a weakness known only to the NSA, then random contractors (like Snowden) could use that to extract money from the Bitcoin network, which uses SHA256 as its core cryptographic primitive. That's easily a billion dollar motivation right there, and I can't imagine a bunch of low-paid government drones resisting that cash prize. Everyone has a price. Hence, there's a level of trust that can be gained through observation of failures to abuse backdoors. If they don't exist, they can't be abused. If they exist, then they must be used/abused, otherwise what's the point? Such usage will be eventually discovered. E.g.: The use of the Dual_EC_DRBG back-door to tap into Juniper VPN connections by the Chinese government was discovered and made public.
- leetbulb 3y ago
  I'm not advocating in either direction here, but let's assume backdoors like this do exist: Just because they haven't been abused doesn't mean that they wont in the future. Of the people I know that work with highly privileged materials, none would take advantage or abuse something like this, even with such a high payout. Even if they did, how would they continue to live comfortably? That said, it just takes one person under the right circumstances to act maliciously, which is why screening and compartmentalization is critically important for these organizations.
  - jiggawatts 3y ago
    The SHA2 standard is now 22 years old. That's an awfully long wait to start utilising a back door!
dllthomas 3y ago
Interestingly, Trusting Trust style attacks on compilers was later (theoretically, idk to what degree it's been put into practice) solved by "diverse double compiling": https://dwheeler.com/trusting-trust/ https://dwheeler.com/trusting-trust/

jiggawatts 3y ago

There are some algorithms where there's no obvious way to back door it, but it's always conceivable -- the person designing it may know some clever mathematics that you don't. With Dual_EC_DRBG, everyone knew that it could be back doored. It's not some guess, or "maybe it could have". It was obviously designed to be back doored. It should have been called "NSA_BACKDOOR_RNG", because that's literally what it is. And yes, all organisations that are not under the thumb of the US Government laughed at the transparent attempt to introduce a back door and rejected Dual_EC_DRBG. Only US-based companies use it, which ought to give you a hint.

thephyber 3y ago

The “need” for proof here determines whether there was likely malicious intent or negligence/ignorance. People who live in an evidence-based rational world don’t skip the evidence step and go straight to possibilities and counterfactuals.

samplatt 3y ago
There's a certain point in the security world where paranoia becomes a requirement, even though it only breeds more paranoia. An outcome of this is the requirement to treat all possibilities as certainties, regardless of evidence. In this way, entire sections of industry will auto-assume the backdoor was both deliberate, and used both both friendlies & hostiles.
- AnthonyMouse 3y ago
  Knowledge that this environment exists is also strong evidence that it was a backdoor. If you propose a clearly questionable security practice in some arbitrary bureaucracy, the assumption is it's incompetence because that happens all the time and no one detects it until it's already in production. If you propose a clearly questionable security practice to a cryptography standards body, the expectation is that you get laughed out of the room. Even the possibility of a backdoor would make everyone skeptical, which would be useless in a standard because no one would trust it. And yet it made it through the standards process for some reason, but there is only one plausible reason.
- thephyber 3y ago
  > In this way, entire sections of industry will auto-assume the backdoor was both deliberate, and used both both friendlies & hostiles. That’s fine. But they should be equally paranoid of all substitute products/services that use other recommendations from NIST, right? Are there greater than zero products on the (US) market with no encryption in the system recommended by NIST? Also, I don’t think I was limiting my thinking to a customer of the weak encryption product. I was also thinking through the lens of legal implications.
jacquesm 3y ago