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1d
revised How does reuse attack protection (RAP) work?
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revised How does reuse attack protection (RAP) work?
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answered How does reuse attack protection (RAP) work?
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comment USB TEMPEST attacks: viable range?
I'm unaware of any papers, and any properly informed replies would likely have to involve a serious amount of research into the practicality of it. It's also going to be hugely variant on the individual implementation - something as trivial as the location and shape of ground and power planes might vastly alter the amount of EMI that's emitted.
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comment Ransomware doesn't change file extension after encryption
@JeanCarlosSuárezMarranzini Not off the top of my head. There are so many out there, both prevalent and less-so, that it's almost impossible to guess in most cases from behaviour like this. As you noted, the ransom note is a much better indicator.
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comment Ransomware doesn't change file extension after encryption
@JeffMeden Or it could just add a known identifier to the start (or end) of the file contents to show it was encrypted. Or just assume that, after its first run, all file types with specific extensions were already encrypted. The possibilities are numerous.
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comment What are the disadvantages of using public key cryptography when encrypting files?
You're also forgetting that asymmetric crypto is incredibly slow on large data sets. Algorithms such as RSA have a requirement that the data being "encrypted" is smaller than the key. Trying to encrypt even a few tens of kilobytes would take a huge amount of computing time. By comparison, symmetric algorithms are incredibly fast.
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answered Ransomware doesn't change file extension after encryption
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comment To what extent does formatting a disk (securely) remove its data?
@Mindwin Then take the same approach with TLS, password hashing, and everything else. Your position is ridiculous from a practical perspective. Might AES be broken in future? Sure. Might a meteor wipe the planet out? Sure. But within the foreseeable future it's fine, nobody needs to panic, and planning / compensating for it is a complete waste of your time on this planet. Feasibly speaking a discarded key renders AES-encrypted data unreadable. Your data is, in all practical senses, gone.
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comment To what extent does formatting a disk (securely) remove its data?
@Mindwin No, 256-bit keys are physically impossible to brute-force due to the energy required; a classical computer would require more energy than the universe contains, and even with Grover's algorithm a quantum computer would require 2^128 operations and a large gate cost, which still requires almost as much energy as we can observe in the known universe. It is physically impossible from a brute-force perspective. Judging by cryptographic attacks from the past hundred years, feasible ciphertext-only exploits are far and few even with seriously weaker designs than AES.
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comment To what extent does formatting a disk (securely) remove its data?
@Mindwin Since 256-bit keys are physically impossible to bruteforce, I wouldn't worry about it.
Apr
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comment To what extent does formatting a disk (securely) remove its data?
@Nayuki I've never heard that either. My understanding is it overwrites each sector.
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27
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27
answered How to protect from WPAD attacks?
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revised To what extent does formatting a disk (securely) remove its data?
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Apr
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answered To what extent does formatting a disk (securely) remove its data?
Apr
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comment Store password ciphers using Powershell ? DPAPI/AES
@Svart You didn't make this clear at all in your question. In which case, have the script take a master password, produce 384 bits (48 bytes) with it using PBKDF2 (e.g. .NET's Rfc2898DeriveBytes class), then split that into three 128-bit values for encryption key, IV, and authenticity key. Use the first two to encrypt the message with AES-128, and use the last one as a key for a HMAC-SHA256 signature on the encrypted data. That way the administrator only needs to enter a master password to launch the script, and an attacker can't decrypt or change the encrypted data.