61–70 of 111 posts
Earlier quoted context omitted.
Thank you. I read the article in some detail, I didn't read the author's name. The author's gender is not evident from the text of the item. For what it's worth, I found your comment somewhat snarky.
"... and about dispatching her daughter to the Coin Cafe A.T.M. at the 11th hour." I agree about the snarkiness though.
Has anyone ever done a serious technological evaluation of one of these programs? I'd be very interesting in learning more specifically about its encryption mechanism. For example, To be able to decrypt (edit: used to say encrypt) the files, it has to store the private key (and obviously the public key) somewhere on the computer, whether in memory or elsewhere to decrypt the files. In addition to this, if this is a v…
> To be able to encrypt the files, it has to store the private key (and obviously the public key) somewhere on the computer Why do you say that? The very purpose of public-key crypto is so that you can send only the public key, have the other end encrypt with that, while you hold onto the private key which is the only thing that can decrypt it. No guarantee this uses public key for the crypto though. From what I know…
Has anyone ever done a serious technological evaluation of one of these programs? I'd be very interesting in learning more specifically about its encryption mechanism. For example, To be able to decrypt (edit: used to say encrypt) the files, it has to store the private key (and obviously the public key) somewhere on the computer, whether in memory or elsewhere to decrypt the files. In addition to this, if this is a v…
Each file gets its own key, and those keys are stored on the victim's computer, encrypted with a single key.
DeCryptoLocker can defeat the encryption and restore your files[2].
Symantec says CryptoWall similarly uses public-key encryption with a 2048-byte key[3], but no indication if it can be defeated like CryptoLocker was.
[1] https://news.ycombinator.com/item?id=8834012
[2] https://www.decryptcryptolocker.com/
[3] http://www.symantec.com/security_response/writeup.jsp?docid=...
Has anyone ever done a serious technological evaluation of one of these programs? I'd be very interesting in learning more specifically about its encryption mechanism. For example, To be able to decrypt (edit: used to say encrypt) the files, it has to store the private key (and obviously the public key) somewhere on the computer, whether in memory or elsewhere to decrypt the files. In addition to this, if this is a v…
> To be able to encrypt the files, it has to store the private key (and obviously the public key) somewhere on the computer Why do you say that? The very purpose of public-key crypto is so that you can send only the public key, have the other end encrypt with that, while you hold onto the private key which is the only thing that can decrypt it. No guarantee this uses public key for the crypto though. From what I know…
Symmetric key encryption is more efficient, but the typical approach when using public key encryption with large files is to use symmetric key encryption, then encrypt the symmetric key with the public key, and then transmit that over the wire.
I imagine that the process used in this software is the following:
1. Generate symmetric key
2. Encrypt symmetric key using (known) public key (the private key remains on the malware owner's servers)
3. Delete the unencrypted symmetric key.
If these three steps are done before the user is told that their files have been held hostage, then by the time that they know they are infected, it's too late to do any analysis of the program, sniff memory, etc. (at best they'll be able to recover the public key and the encrypted symmetric key, which is useless without the corresponding private key). As soon as the ransom is paid, the malware owners will decrypt the symmetric key (using their private key), and send that back to the victim[0].
This could, of course, also use a different symmetric key for each file as well, in addition to the above.
[0] In theory, the malware owners don't even need to store anything per-victim, since the encrypted symmetric key can remain "safely" with the users the entire time. All they need to store is the single master private key.
Has anyone ever done a serious technological evaluation of one of these programs? I'd be very interesting in learning more specifically about its encryption mechanism. For example, To be able to decrypt (edit: used to say encrypt) the files, it has to store the private key (and obviously the public key) somewhere on the computer, whether in memory or elsewhere to decrypt the files. In addition to this, if this is a v…
It doesn't have to know the private key, just the public one, woth the private being on the virus-owner's side. Furthermore, it's possible to encrypt each file with a different key so one public key would only deceypt one file. Oh, and a fun fact - with the newest cryptography algorithms it's even possible to modify the files without knowing what they contain. If I'm not mistaken it would even be possoble to create a…
To my knowledge, this is only true in a purely academic (not practical) sense at present. There do exist homomorphic encryption schemes but current implementations are ridiculously slow.
Has anyone ever done a serious technological evaluation of one of these programs? I'd be very interesting in learning more specifically about its encryption mechanism. For example, To be able to decrypt (edit: used to say encrypt) the files, it has to store the private key (and obviously the public key) somewhere on the computer, whether in memory or elsewhere to decrypt the files. In addition to this, if this is a v…
The program has to encrypt them, unlink the files, and save the encrypted files / archive. If the filesystem needs more space later, it writes over those (discarded) files, right? Everything else would increase disk wear and decrease performance.
Edit: of course excluding SSDs with TRIM/discard enabled.
Isn't this a pretty strong argument against Bitcoin and other cryptocurrencies? (I am being serious.)
Pre-Bitcoin, the scammer would have her call an expensive foreign premium-rate phone number or mail cash to a foreign address.
Isn't this a pretty strong argument against Bitcoin and other cryptocurrencies? (I am being serious.)
Not really. Most useful technologies can be used in crime and we'd get nowhere if we allowed that fact to be used as an argument against the technology. Pre-Bitcoin, the scammer would have her call an expensive foreign premium-rate phone number or mail cash to a foreign address.
I love the elegance of the bitcoin protocol, but I am worred that the civilized world will have to clamp down on it. You just can't have a place where anyone with enough money (a few k EUR/USD) can perform murders without any reasonable risk of being exposed. This will effectively turn us into a bandit country like Russia. I also think it will become harder to effecticely clamp down on cryptocurrencies as time passes, so time is of an essence.
Earlier quoted context omitted.
Indeed, having a recent valid backup turns the cryptolocker variety of virus quite ineffective, you only lose some time to restore vs files you can't replace. But how is this related to the internet or the cloud in any way? Putting backups into the cloud is a terrible idea and transferring large data collection over a residential Internet connection makes little sense. Backups for home users became a possibility with…
I did not say put it in the cloud. Although it is totally possible to create backup solution that is undecryptable by the cloud hosting provider.