78 votes
Accepted

How to decrypt .lock files from ransomeware on Windows

I don't think you will see those files again, unless you have a back up. You can view the transaction history of the Bitcoin address you were asked to pay to here. As you can see, there are 303 ...
Anders's user avatar
  • 65.6k
64 votes
Accepted

Is there any hope of getting my pictures back after an iPhone factory reset some day in the future?

Modern encryption is strong enough that there is no way to retrieve the lost data without the key. Although it's possible that it could be doable in the future in theory, consider that even the cipher ...
forest's user avatar
  • 66.6k
62 votes
Accepted

Is there such a thing as a "Black Box" that decrypts Internet traffic?

Yes. It's called a Man-in-the-Middle attack. You terminate the SSL session at a mid-point, thereby having the encryption key, then create a new session to the target server, so you have that ...
Matthew's user avatar
  • 27.4k
57 votes
Accepted

Encrypting text file with AES 256 instead of password manager

Considering those compromises you mention, do you think that encrypting files yourself will be easy? How do you know you won't get into those same pitfalls that resulted in compromises of password ...
Dmitry Grigoryev's user avatar
51 votes
Accepted

Why haven't (most of) the Zodiac Killer's letters been decrypted?

The Zodiac killer ciphers are an interesting case. As there were four ciphers sent to the local papers, I will address each in turn. They do share some common traits however. They are each their own ...
WhataTiberius's user avatar
48 votes
Accepted

Is it possible to recover a lost passphrase for a private key file?

The whole point of having a passphrase is to lock out anyone who does not know it. Allowing it to be recovered would defy the principle and allow hackers who get access to your certificate to recover ...
M'vy's user avatar
  • 13k
36 votes

How To Recover End-To-End Encrypted Data After Losing Private Key?

You have found another example of the balance security vs usability. If you want true E2E encryption, end users are responsible for their keys and for possible backups of their messages. Full stop. If ...
Serge Ballesta's user avatar
34 votes
Accepted

What will I get if I "decrypt" a plaintext?

"Encryption" is a large term. In all generality, encryption takes an input message in some space of possible input messages; usually arbitrary "sequences of bits" with various restrictions on length, ...
Tom Leek's user avatar
  • 172k
34 votes

Is there such a thing as a "Black Box" that decrypts Internet traffic?

No, there's no way such a thing could possibly exist, for any significant amount of time. There's two big hints at this in the article itself: many technical experts are raising equally serious ...
watchowl's user avatar
  • 5,458
31 votes

Is there any hope of getting my pictures back after an iPhone factory reset some day in the future?

Every time I updated my iPhone with iTunes, iTunes automatically made a backup of the iPhone. These backups can be checked in: iTunes >> Edit Menu >> Preference >> Devices >> ...
Henk Groot's user avatar
26 votes

Why haven't (most of) the Zodiac Killer's letters been decrypted?

You're assuming that they're actually encrypted. A lot of crazy people have written things that nobody understands. Just because the author thinks they're in code doesn't necessarily mean that the ...
tylerl's user avatar
  • 83.3k
21 votes

How to decrypt .lock files from ransomeware on Windows

First line of defense: BACKUPS. Restore the files from there. When available, this has a 100% chance of success. Otherwise: hope that the ransomware did not disable/work around the Windows Shadow ...
LSerni's user avatar
  • 22.8k
19 votes

How To Recover End-To-End Encrypted Data After Losing Private Key?

If user changes the device, reinstalls the app, private key which stored on client will be lost. I know i can create new key pairs for future messages but how can i restore the old ones? Why do you ...
vidarlo's user avatar
  • 16k
18 votes

Is it possible to recover a lost passphrase for a private key file?

From your description, it sounds like the server is currently using the key, which means the server "knows" the pass phrase. If this is correct and you have appropriate access to the server, you ...
Gordon Davisson's user avatar
16 votes

How to decrypt .lock files from ransomeware on Windows

Europol has a web page with a contact form that you can use to check if a solution is available to your friend's problem. https://www.nomoreransom.org/
jedidog's user avatar
  • 304
16 votes
Accepted

Has anybody successfully decrypted their files after paying the WannaCrypt ransom?

Yes, some have apparently gotten their files decrypted after paying the ransom. We have confirmation that some of the 200+ #WannaCry victims who have paid the ransom have gotten their files back. ...
Arminius's user avatar
  • 44.7k
16 votes
Accepted

Extracting openssl pre-master secret from apache2

Apache om Debian 9 (Stretch) uses OpenSSL 1.0.2 (see apache2-bin dependency on libssl1.0), so you can use the approaches documented in that linked post. You can modify the startup script to export ...
Lekensteyn's user avatar
  • 6,088
14 votes

Why can't SHA256 be decrypted?

First, there is a difference between hashing and encryption. SHA256 is a hashing function, not an encryption function. Secondly, since SHA256 is not an encryption function, it cannot be decrypted. ...
Cyker's user avatar
  • 1,683
14 votes
Accepted

If a WAF is compromised, can the adversary view all the traffic in clear text provided WAF uses SSL cert to decrypt it?

Yes, the configuration is as follows: [client web browser] <--TLS--> [WAF] <--TLS--> [origin web server] So, the WAF essentially has a 'man in the middle' (MITM) position between the ...
mti2935's user avatar
  • 23.4k
12 votes

Is there such a thing as a "Black Box" that decrypts Internet traffic?

The black box is theoretically possible, but is practically impossible. In order for it to work the CAs would have to cooperate and be willing to provide the Black Box with legitimate certificates for ...
TTT's user avatar
  • 9,202
12 votes

Encrypting text file with AES 256 instead of password manager

You'd lose the ability to generate random passwords at the click of a button, which might mean you tend towards weaker passwords from the lack of convenience - one of the benefits of password manager ...
Matthew's user avatar
  • 27.4k
11 votes

Why can't the FBI copy the contents of an iPhone they are trying to crack?

When trying to access the content of a hard-drive, you have to use the interface provided by said hard-drive. It usually comes with a firmware. Currently, it is stated that this firmware will not ...
M'vy's user avatar
  • 13k
11 votes

Is it possible to recover a lost passphrase for a private key file?

Under some circumstances it may be possible to recover the private key with a new password. It would require the issuing CA to have created the certificate with support for private key recovery. This ...
Jenny D's user avatar
  • 1,197
10 votes

Are these claims about modern CPUs and AES decryption true?

AES decryption with the key can definitly happen at GB/s on modern Intel CPUs. Brute-forcing the entire AES keyspace (e.g. 2^128 possibilities) is considered impossible today by a very large margin (...
flakeshake's user avatar
10 votes
Accepted

Best way to know the algorithm used for a password encryption

How are passwords stored? Passwords are not (or at least should not be) stored using encryption. They should be stored using a hashing algorithm. So if you are trying to decrypt it to recover the ...
Mike Ounsworth's user avatar
9 votes
Accepted

How to decrypt a message using only session key?

To encrypt a file for a recipient: $ gpg -ea -r [email protected] < file > file.gpg To get the session key for an encrypted file when you have the private key of the recipient: $ gpg --show-...
Steffen Ullrich's user avatar
9 votes
Accepted

Web-based secret manager using CryptoJS

Potential issues: What kind of client are you envisioning? If it's web-based, or anything else that pulls code (scripts, etc.) from the server, it's ~impossible to make it secure against a malicious ...
CBHacking's user avatar
  • 47.6k
9 votes
Accepted

What makes a symmetric encryption algorithm cryptographically secure?

When you design an encryption algorithm, you generally want it to be secure in as many use cases as possible. This would allow you to reuse the same algorithm everywhere, saving a lot of resources and ...
nobody's user avatar
  • 11.5k
8 votes

Is it possible to recover a lost passphrase for a private key file?

As far as our current knowledge goes, there is only brute force available. Ask the person who created the key to try to remember the passphrase and try. If this is not available, try a cracking ...
Sir Cornflakes's user avatar
8 votes
Accepted

How to read password from Windows credentials?

The Credential Manager stored passwords are managed by the Data Protection API and protected by DPAPI "master keys": The DPAPI keys used for encrypting the user's RSA keys are stored under %...
Royce Williams's user avatar

Only top scored, non community-wiki answers of a minimum length are eligible