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2d
comment Signal listening
Don't forget the doggy door with the proximity unlocking mechanism. That one is listening, too.
Feb
5
comment Is there an encryption algorithm that is fully secure?
"if they can keep that message from getting to your target, and do so in a way that you aren’t aware of this, they can completely break your communication channel" Cryptography cannot protect you against this type of attack.
Feb
5
comment Is there an encryption algorithm that is fully secure?
"Fully secure" against what attack, exactly?
Feb
5
comment Is there an encryption algorithm that is fully secure?
OTPs, or at least naiive implementations of OTPs, are however malleable, which means that a part of the message can be changed undetectably. An OTP must be coupled with a MAC (message authentication code) to provide protection against ciphertext modification, but once you have a MAC, chances are pretty good that the combined system no longer possesses the OTP's information-theory confidentiality guarantees because you can then guess keys and try to validate the MAC.
Feb
5
comment Why don't OSes protect against untrusted USB keyboards?
@R.. Let's say you have something like a Logitech Unifying Receiver working with your keyboard and mouse. Now, it breaks, and your local electronics store doesn't have any Logitech hardware but does stock Microsoft mice and keyboards. Explain to me how you would resolve this situation, in the scenario you describe, in a way that doesn't bring us right back to square one security-wise with regards to untrusted USB devices.
Feb
3
comment Why do security experts like Snowden use email services like Lavabit and Hushmail rather than self-hosted email?
@hobbs Indeed; that's the entire principle behind email greylisting, and why it works so well for blocking spam at minimal risk of blocking legitimate traffic.
Feb
2
comment What else can I do to protect my accounts?
@iProgram If you want to discuss this, you might want to give Information Security Chat a try. The main site is specifically for questions that allow for a single, authoritative answer. See for example How do I ask a good question? in the help center.
Feb
1
revised Would a Rubik's cube be a trapdoor function?
Copy-editing
Feb
1
suggested approved edit on Would a Rubik's cube be a trapdoor function?
Jan
31
comment Loss of physical locks/password to safes
@Anti-weakpasswords I think that's fairly common for copy-protected keys, actually. Different manufacturers do it in different ways (for d12 Assa uses a separate physical token that is has information on it that is needed to make new keys or locks, for example) but however it is done, there exists some sort of authorization or authentication besides the key. When blanks are controlled and cutting data is restricted, that serves to make obtaining duplicate keys much more difficult. The key is still just a physical token that can be copied given enough effort, but this definitely raises the bar.
Jan
29
comment Loss of physical locks/password to safes
Ah, yes, that too. Of course, for most people for whom this is a problem that needs considering, master keys is not often a major issue.
Jan
29
comment How would I prove a windows executable is not a false positive?
"Prove" to whom?
Jan
29
comment Loss of physical locks/password to safes
"if you knew that your front door key was a Schlage 24431, you could go to a locksmith and have them use a Schlage blank and create a 24431 key and it would probably work." That's why it might be a good idea to use copy-protected keys (examples being Assa d12, Kaba and others), ideally without key numbers stamped on them. Doing so doesn't stop the really determined people from copying the key, but it does make it much more difficult.
Jan
26
comment Why doesn't changing the PIN affect recorded data on magnetic card?
With only 10,000 possible values, hashing of any kind that can be accomplished in an amount of time that is acceptable at the checkout is rather pointless. (Consider a 1 second work factor. Checking all values then takes about 2 hours 45 minutes, at most, and can be trivially parallellized.) Better to ensure that the data cannot be illegitimately read or written.
Jan
24
comment About the AES algorithm key and ciphertext
SHA-1 has a 160 bit output hash, not 128 bits. I think the only hash algorithm that is both reasonably common and has a 128 bit output hash is MD5, which I would be wary of using even in a PBKDF these days. SHA-1 is OK (the currently discussed attacks on it are irrelevant for KDFs) and SHA-2 should be even better (as in "two times infinity is infinity" better).
Jan
23
revised Is firefox disabling of insecure TLS fallback part of the HSTS spec?
added 1190 characters in body
Jan
22
comment Is firefox disabling of insecure TLS fallback part of the HSTS spec?
@gtmcclinton If the host is not a known HSTS host, being able to click through a security warning is allowed because it is the default (non-HSTS) behavior. Once the host is known as a HSTS host, if you are still able to click through, I would probably argue that that's a bug.
Jan
22
awarded  Tag Editor
Jan
22
revised hsts wiki excerpt
Mention the HSTS RFC
Jan
22
suggested approved edit on hsts tag wiki excerpt