coppsilgold

8 ms·

91.
by coppsilgold 8mo ago
> Is your concern the secure enclave in an iPhone is deflatable, and in such a way as to allow key extraction of device unique seeds it protects? This is a safe assumption to make as the secret bits are sitting in a static location known
92.
by coppsilgold 8mo ago
> I recommend reading the AES-XTS spec, in particular the “tweak”. Or for AES-GCM look at how IV works. What does this have to with anything? Tweakable block ciphers or XTS which converts a block cipher to be tweakable operate with an ac
93.
by coppsilgold 8mo ago
I would not recommend that one trust a secure enclave with full disk encryption (FDE). This is what you are doing when your password/PIN/fingerprint can't contain sufficient entropy to derive a secure encryption key. The prob
94.
by coppsilgold 9mo ago
The way bitcoin works is that addresses are hashes of a public key. This technically allows for an emergency measure in case ECC is broken by a quantum computer: The [unknown] public key becomes the private key. The signature becomes a ZKP
95.
by coppsilgold 9mo ago
No closed-source E2EE client can be truly secure because the ends of e2e are opaque. Detecting backdoors is only truly feasible with open source software and even then it can difficult. A backdoor can be a subtle remote code execution &quot
96.
by coppsilgold 9mo ago
My understanding is that it has gotten fairly complex. Don't know if they still use this particular facet but look at the Fourier-Mellin transform: < https://sthoduka.github.io/imreg_fmt/docs/fourier-mellin-
97.
by coppsilgold 9mo ago
Then this is either an exploit or more likely the mp4 file is virtual. You can find out if you are so inclined by grabbing it from two separate accounts using two separate devices (or keys) and then compare how many of the segments are iden
98.
by coppsilgold 9mo ago
Have you inspected the contents of their CDN servers? Because assembling an mp4 on the fly from segments is not difficult. Especially if they condition them to have identical sizes.
99.
by coppsilgold 9mo ago
A/B watermarking is about static content on CDNs... For every segment in a video there will be two versions. Every user will get a unique sequence of segments served to them.
100.
by coppsilgold 9mo ago
> To what extent does this watermarking survive transcoding? Would not transcoding multiple times possibly affect it? They are designed to survive being recorded by a phone at an angle. The embedding is only 1-bit per segment which can b
101.
by coppsilgold 9mo ago
They can trace a torrented 4K piece of content to the device (or private key) that ripped it using A/B watermarking. See AWS offering: (and probably what they use for Prime Video, Netflix has their own) For large-scale per-viewer,
102.
by coppsilgold 9mo ago
The idea behind blind signatures is that the server will give you a signed token which is blinded and you can un-blind it on your end and then use it. The consumer of the token will not be able to collude with the issuer of the token to fig
103.
by coppsilgold 9mo ago
It's a privacy consideration. If you desire to juggle multiple private profiles on a single device extreme care needs to be taken to ensure that at most one profile (the one tied to your real identity) has access to either attestation
104.
by coppsilgold 9mo ago
> Anonymous-attestation protocols are well known in cryptography, and some are standardized: https://en.wikipedia.org/wiki/Direct_Anonymous_Attestation Which does exactly what I said. Full zero knowledge attestation
105.
by coppsilgold 9mo ago
Remote attestation only works because your CPU's secure enclave has a private key burned-in (fused) into it at the factory. It is then provisioned with a digital certificate for its public key by the manufacturer. Every time you perfor
106.
by coppsilgold 9mo ago
I usually just edit ~/.config/mimeapps.list directly. I can see how that tool can be useful, but only if it's included in official repos. Editing mimeapps.list is simpler than the hassle of downloading and building this tool.
107.
by coppsilgold 9mo ago
> A six digit PIN you use to unlock your phone or messaging app doesn't have enough entropy to be secure The PIN is not usually used for cryptography, it's used to authorize the TEE (secure enclave) to do it for you. It's
108.
by coppsilgold 9mo ago
> The sophisticated version I heard is to make the differences in the white space between individual words/lines/wherever. That would be a naive way to do it. Here is an example of a more sophisticated way: A canary trap is
109.
by coppsilgold 9mo ago
It's more sophisticated than that. A single movie can be fragmented into 1000s of fragments, each fragment carries 1 bit. It's called A/B forensic watermarking. So you need to insert a 1-bit watermark into a video segment tha
110.
by coppsilgold 9mo ago
It would be natural for a leaker to assume that the PDF contains something "extra" and to try and and remove it with this method. It may not occur to them that this something extra could be part of the content they are going to ge
111.
by coppsilgold 9mo ago
> I don't think watermarking is a winning game for the watermarker, with enough copies any errors can be cancelled. This is a very common assumption that turns out to be false. There are Tardos probabilistic codes (see the paper I l
112.
by coppsilgold 9mo ago
While useful it needs a big red warning to potential leakers. If they were personally served documents (such as via email, while logged in, etc) there really isn't much that can be done to ascertain the safety of leaking it. It's
113.
by coppsilgold 9mo ago
Note that during remote attestation you are deliberately leaking a unique static hardware ID to the one you are attesting to. There is usually some measure of indirection involved (EK -> AIK) such that additional collusion is required to
114.
by coppsilgold 9mo ago
Usually both sides have an expert witness, the implications of that are self-evident. Don't even need to factor in knowledge about human nature to understand what is happening. To be fair, the deviation from the truth an expert witness
115.
by coppsilgold 9mo ago
> Can you imagine if you ask an engineer "what's your opinion on the maximum load this bridge can take?" he answered "for a fee, I will claim that my opinion is what you tell me". https://en.wikipedia.
116.
by coppsilgold 9mo ago
Many WiFi chips can be put into monitor mode (process all the data packets it can detect over the air) and inject packets for transmissions themselves. This pathway is typically unoptimized and would offer poor bandwidth but it is enough fo
117.
by coppsilgold 9mo ago
Note that bubblewrap can't protect you from misconfiguration, a kernel exploit or if you expose sensitive protocols to the workload inside (eg. x11 or even Wayland without a security context). Generally, it will do a passable job in pr
118.
by coppsilgold 9mo ago
JPEG XL has progressive decoding https://www.youtube.com/watch?v=UphN1_7nP8U
119.
by coppsilgold 9mo ago
It takes skill to make a GUI that integrates dynamic information a good UX. For things like WiFi I discovered that modifying config files is an infinitely better experience than any GUI on Linux. Also for some reason DE's sometimes fai
120.
by coppsilgold 9mo ago
Ultimately what he is suggesting to do is to bind a string of entropy to a website through facilitation of the browser and a Passkey. A cryptographic seed is one of the most sensitive things. And here you choose to expose it to a website (e

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