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106 votes
Accepted

Is layered encryption more secure than long passwords?

Option 1 is more secure. In option 2, we can guess each word seperately. When we guess "amazing", we get confirmation that this word is correct and we can continue to the second word. In option 1, we ...
Sjoerd's user avatar
  • 30.8k
70 votes
Accepted

Is it a coincidence that the first 4 bytes of a PGP/GPG file are ellipsis, smile, female sign and a heart?

Yes, it's a coincidence that the first bytes appear to you as these symbols. They are part of the OpenPGP message format specification (RFC 4880) and vary depending on the packet properties. Let's ...
Arminius's user avatar
  • 44.8k
60 votes
Accepted

Encrypting a few TB of Data

Why not use a commonly used application to do it? VeraCrypt is a good choice as it replaced the respected TrueCrypt application and allows you to create an encryption container that you mount as a ...
ISMSDEV's user avatar
  • 3,280
53 votes
Accepted

Who owns the gpg key 4AEE18F83AFDEB23 and how did it sign a commit in my GitHub repo?

GitHub itself is signing commits made through the online editor using the key 0x4AEE18F83AFDEB23: From: https://help.github.com/articles/about-gpg/ GitHub will automatically sign commits you make ...
Jonathan Cross's user avatar
49 votes
Accepted

How to raise a key to ultimate trust on another machine?

You can set every key to ultimate trust through opening the key edit command line gpg --edit-key [key-id] and running the trust command. You will now be prompted to select the trust level: Please ...
Jens Erat's user avatar
  • 24.6k
41 votes

Encrypting a few TB of Data

I find some of your comments curious. Particularly, I'm trying to stay away from methods that are reliant on an application, and do it manually - as I'd feel more in 'control'. and I don't need ...
user's user avatar
  • 7,795
36 votes

Can I add an email address to an existing GPG key?

Yes, you can add user IDs. The key is still the same, so you can use it like before. The only difference is that any possibly existing signatures are not valid for the new user IDs. Find out the key ...
Esa Jokinen's user avatar
29 votes
Accepted

GPG why is my trusted key not certified with a trusted signature?

The key needs to be verified. If you trust that someone's public key does in fact belong to that individual and they are in your keyring you can use your private key to sign your correspondent's ...
TheJulyPlot's user avatar
  • 7,809
29 votes

Is layered encryption more secure than long passwords?

This doesn't add security, but makes it easier to guess the passphrase one word at a time (N⁴ vs. N+N+N+N, where N is the symbol count of the word list). Even when you encrypt a file or a message to ...
Esa Jokinen's user avatar
26 votes
Accepted

GPG masterkey and subkey for encryption and signature and default keys

If you already have an SC and E keys, and you want to remove your C ("master") key to offline storage, then all you require is a new S key (SSK1 in your example). You do not need to create a new ...
mricon's user avatar
  • 6,538
26 votes
Accepted

How do GPG smart card devices handle large GPG operations?

The only secret information involved in the digital signature process is the private key. Everything else is public info. So you can hash the large "message" (file, whatever) in software, ...
CBHacking's user avatar
  • 48.9k
24 votes
Accepted

How to change (sub)key usage of a PGP key?

Since GnuPG 2.2.6 there's a hidden key-edit subcommand "change-usage" which does exactly that. Relevant commit. Let's try this subcommand with a test key. Let's create one first: mkdir /tmp/gpg-...
sanmai's user avatar
  • 464
24 votes
Accepted

Is there a limit on the layers of encryption a file can have?

Theoretically, there's no limit on the number of times you can encrypt a file. The output of an encryption process is again a file, which you can again pass it on to a different algorithm and get an ...
pri's user avatar
  • 4,446
21 votes
Accepted

What is the difference between Key, Certificate and Signing in GPG?

In public key cryptography, the key is usually a key pair, consisting of a public key and a private key, and it is what you do encryption, decryption, signing, and verification with. "A key ...
Matei David's user avatar
21 votes
Accepted

gpg --fingerprint prints out completely different fingerprint

GnuPG generally resolves subkeys to the primary key if a subkey is passed as argument. This might be especially surprising when specifying an encryption subkey: GnuPG resolves the subkey to the ...
Jens Erat's user avatar
  • 24.6k
21 votes
Accepted

Sending the GPG key to keyserver

The PGP keyserver pool has dozens (129 at the moment) of keyservers in it. When you make a request to it, you may get a different server than the previous request. Over time, the keyservers all ...
David's user avatar
  • 16.1k
21 votes
Accepted

gpg2: How to get rid of "Please insert card with serial number", getting the same key from a different card / Yubikey

Solution Delete the keygrips of the keys in question from ~/.gnupg/private-keys-v1.d. You can list the keygrip IDs using gpg --list-secret-keys --with-keygrip. If all your private keys are on ...
nh2's user avatar
  • 583
21 votes
Accepted

Where are the symmetric keys stored?

This is actually how PGP/GPG operates. When you encrypt something to a public key, it first encrypts the data with a symmetric key. Then it encrypts the symmetric key with public key cryptography, and ...
vidarlo's user avatar
  • 16.5k
20 votes

Can I specify a public key file instead of recipient when encrypting with GPG

Since GnuPG 2.1.14 there is a new option allowing to encrypt from a keyfile: --recipient-file FILENAME. It works from an binary or an ascii armored file. Check the release notes or the dev mailing ...
Dorsug's user avatar
  • 301
19 votes
Accepted

Is it safe to share your `gitconfig`'s `user.signingkey` value with the world?

Is it safe to share your gitconfig's user.signingkey value with the world? Yes, that is safe. The signingkey value is your GPG key ID (the lower 64 bits of the fingerprint) which is derived from ...
Arminius's user avatar
  • 44.8k
19 votes

Is layered encryption more secure than long passwords?

Imagine a Hollywood film where they're cracking a password or a security code, with all the spinning digits on a fancy UI, and they have elite hackers who crack one digit of the code at a time, and ...
Muzer's user avatar
  • 291
18 votes

Putting my PGP ID/link on printed business cards

I'd recommend putting your OpenPGP key's fingerprint in textual form and as QR code on your business card. To do so, you would create an URI with OPENPGP4FPR as scheme and your OpenPGP fingerprint in ...
Flow's user avatar
  • 344
18 votes
Accepted

Is there a common best practice for naming public and private PGP keys when exporting them?

While obviously it's very hard to prove a negative, I think that the reason why you have found no such "common best practice" is that none exists. The key itself doesn't care about its file name. ...
user's user avatar
  • 7,795
18 votes

Is it a coincidence that the first 4 bytes of a PGP/GPG file are ellipsis, smile, female sign and a heart?

As a general principle, well-designed binary file formats¹ will have their first few bytes be a magic number identifying the format. ELF executables' first four bytes are always 7f 45 4c 46, PNG ...
zwol's user avatar
  • 647
16 votes
Accepted

Which signing key should I use for certifying other peoples public keys: master or subkey?

The four possible key "usages" are Certification: signing other keys Signing: signing data Encryption: decrypting data Authentication: signing authentication tokens When you look at your key using --...
Simon Richter's user avatar
16 votes

gpg-agent keeps saving pin for a smartcard

I've been looking into this myself. I want to be prompted to enter my PIN every time I request my smart card (Yubikey in my case) to do a sign/encrypt/auth operation. It is possible to enable this ...
Justin's user avatar
  • 161
16 votes
Accepted

Is a part of an encrypted file easier to crack?

No. You still need to find the same length encryption key to decrypt the data into plaintext. Finding the key is the hard part, decrypting a whole or partial image is trivial once you have the key. ...
Monica Apologists Get Out's user avatar
16 votes

Is layered encryption more secure than long passwords?

Another perspective to what the others said (that guessing single words 4 times is much less expensive than guessing a combination of 4 words at once): In cryptography, there is the concept of having ...
AnoE's user avatar
  • 2,409
15 votes

GnuPG decryption not asking for passphrase

GnuPG 2.2.15 --symmetric -c Encrypt with a symmetric cipher using a passphrase. The default sym- metric cipher used is AES-128, but may be chosen with the --cipher-algo ...
anonymous's user avatar
  • 251
14 votes

Is it possible to export a GPG subkey's public component?

use ! to keep gpg from speculating/grabbing primary+secondary keys associated with your keyid [email protected] When using gpg an exclamation mark (!) may be appended to force using the specified ...
droid192's user avatar
  • 260

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