GNU Privacy Guard (GnuPG or GPG) is an open source implementation of PGP, a file encryption and signature tool widely used for emails

learn more… | top users | synonyms (1)

2
votes
1answer
24 views

Multiple OpenPGP encryption keys signed by a single certificatation key?

Say I have several different email accounts and I want to use a different encryption key for each of them but still have them all certified under one identity. Is this a good idea and how would I do ...
5
votes
1answer
12 views

OpenPGP specification and ECC

From OpenPGP specification (RFC 4880) section 13.8 (Reserved Algorithm Numbers): The reserved public-key algorithms, Elliptic Curve (18), ECDSA (19), and X9.42 (21), do not have the necessary ...
4
votes
3answers
1k views

How do I verify someone's identity if the only method of contact is their email address?

Email addresses can be hacked or perhaps even spoofed. I need to pay individuals via paypal and I fear that over time people's email will change or become compromised. How can I ensure I am paying the ...
4
votes
1answer
29 views

Do I need to revoke both my OpenPGP primary key and subkey?

After creating an OpenPGP key pair in GnuPG, if I list keys with gpg --list-keys, I get (GnuPG default): /someone/.gnupg/pubring.gpg ------------------------ pub 2048R/BC589B05 2015-07-15 uid ...
1
vote
0answers
25 views

Is it possible to pass both a message and a public key from stdin to gpg/gpg2? [migrated]

If I have both a message (M) and a public key (P) in a process memory, what would be the way to encrypt M using P without writing either to a temporary intermediate file? Any chance I can pass both ...
8
votes
3answers
877 views

Can I expose a passphrase-protected private OpenPGP key? [duplicate]

I have created a 4096-bit key-pair using GnuPG. Can I expose the passphrase-protected private key to an untrusted system? E.g. can I put that key in my Dropbox account or send it to myself as an ...
2
votes
1answer
44 views

How to use subkeys for encryption and signing with Enigmail?

I'm having an issue with Enigmail. Here's an example to highlight my problem. Alice and Bob wish to communicate securely using Enigmail. For extra security, they both decide to create keys using ...
7
votes
1answer
33 views

GnuPG passphrase entry and X11 sniffing

Each time when I’m entering my passphrase in pinentry-gtk-2, every other X11 app may sniff it, as seen in $ xinput test-xi2 running in the background. What can be done about it? Or do I have to ...
1
vote
1answer
19 views

Why has my OpenPGP key been duplicated on expiry change?

I've published my OpenPGP key publicly on the MIT key server. Later I realized I needed to set the expiry date to an earlier date than the one the (sub-)key was published with. I managed to do this ...
1
vote
1answer
26 views

Is it possible to assign different UIDs to subkeys for the purpose of having multiple identities?

Many people advocate generating new primary keys for each identity they wish to have. For example, creating one primary key and associated subkeys for workplace use, and a completely different ...
2
votes
1answer
22 views

What will happen if my GnuPG passphrase is discovered?

Hypothetically, should I be concerned if someone has my public key and knows my passphrase? Will they be able to decrypt messages sent to me?
0
votes
1answer
42 views

Is there a way to change the creation date of a GPG/PGP cert

How can I modify the creation date of a GPG/PGP key? I can set the Creation-Date while creating a key. But can I change this Creation-Date after the key was created? I cannot find how to do this.
0
votes
1answer
27 views

What does the letter in an OpenPGP key's bits definition (like 4096D) denote?

I noticed that when looking at OpenPGP keys on a key server, the key's bits definition is usually followed by a letter, as in "4096D" for example. However, there are also keys with other letters than ...
0
votes
0answers
12 views

Risk to pgp secret keys with known cleartext/ciphertext? [duplicate]

There are a couple of schemes which encrypt IMAP message stores to yourself using GPG/PGP. Which makes initial sense and would keep casual snoopers from getting email. But it raises a question as ...
1
vote
1answer
24 views

Are PGP/GnuPG trust information transferred to key servers?

When signing a key X in the PGP Web of Trust model, I assign the key full validity. Other people who have my key in their key ring can regard X as valid as far as they fully trust me (owner trust). ...
2
votes
0answers
90 views

Convert RSA openSSH key/putty key to gpg key [closed]

Scenario Two work sites, site 1 and site 2. Two Linux servers, server A and server B. Server A is reachable from both sites, while server B is reachable from site 1 only. Two Windows workstations, ...
0
votes
5answers
166 views

Can I convert a public key to a private key?

I am using pgp4usb for encryption and decryption. I accidentally deleted it but I still have my old (public) PGP key. Is it possible to import it and use it again as my private key? The key is ...
2
votes
1answer
30 views

Merge a second OpenPGP key pair into user id of other key

I have OpenPGP key pairs for two of my email addresses. When I created them, I did not know that it was possible to just add another user id to the first key pair. Then I found out it is possible from ...
2
votes
1answer
40 views

Personal cipher/digest preferences ignored when generating a new key pair in GnuPG

I have specified personal digest preferences in my ~/.gnupg/gpg.conf: personal-digest-preferences SHA512 SHA256 SHA384 SHA224 SHA1 then, I have generated a new key pair. But when I check the ...
1
vote
0answers
64 views

How can I sign an rpm package using a smart card?

I have a smart card (not OpenPGP card), and I am preparing to sign an rpm using this card. After signing, I will get two files: my.rpm.sig, and my_id.cer. How can I sign my rpm using these extra ...
3
votes
1answer
25 views

should ~/.cache/keyring-* be cleared?

I am using gnupg 1.4.15 ls ~/.cache/keyring-* shows many keyring directories. GPG_AGENT_INFO variable is pointing only to the latest one. Should I manually delete all the other keyring agents? Is ...
1
vote
1answer
41 views

Multiple encryption subkeys on hardware smart cards

I've created a PGP key set which consists of the following: A master RSA key with only signing capabilities, stored offline. Multiple OpenPGP cards, each with three RSA keys: An encryption key A ...
0
votes
2answers
44 views

Signing an OpenPGP public key that is not uploaded to a key server

Is there any point in signing an OpenPGP public key that has not been uploaded to a key server? In other words: does anyone except person A who signs person B's public key notice that the signing has ...
1
vote
1answer
55 views

How to change personal cipher/digest preferences of existing OpenPGP key in GnuPG?

The OpenPGP key contains a list of personal algorithm preferences (the meaning of the numbers can be decoded in RFC 4880): # gpg -a --export "foo@example.com" | gpg --list-packets | fgrep 'pref-' ...
2
votes
1answer
159 views

How to tell if my OpenPGP public key is self-signed?

I recently read: You should sign your PGP public key immediately after generating your public/private key-pair. And now I wonder how I can check whether I already did that. So my question is: ...
2
votes
1answer
41 views

Best practice of deprecating old OpenPGP subkeys when migrating to a new subkey pair?

I've been using GnuPG with an offline master + online subkey setup for a while now. All my email is signed with the signing-only subkey and encryption is done with the encryption-only subkey. The ...
2
votes
1answer
62 views

GPG: Can't encrypt DSA 3072 keys

I would like to ask this question as I'm not the first person which has this behavior. I'm trying to encrypt a simple message using GnuPG using a public key I've received from a friend, he's using ...
3
votes
1answer
75 views

How to decrypt email with revoked key in enigmail?

Is it possible to decrypt a message which is encrypted with a revoked PGP key? I still have the private key, but Enigmail doesn't show me revoked keys neither does automatic decryption. Edit: I ...
3
votes
1answer
124 views

toy OpenPGP encryption with manually generated keys

I've been playing around with OpenPGP encryption for a little while. Here are the steps I've followed: Generate an unencrypted public/private key pair in my keyring with gpg --gen-key. Dump the ...
1
vote
0answers
14 views

using crt for encrypting files/texts [duplicate]

I work with GPGTools under Mac where, after creating a public/private key pair for myself, I usually get .asc from other users, import it and then I'm good to go. Now, I got an actual certificate from ...
2
votes
2answers
54 views

Import a subset of private subkeys in GPG

Having trouble with GPG, isolating one set of subkeys from another. In short, I generated a master key, then three subkeys: Signing Encrypting Authorization I can't seem to isolate the Signing ...
4
votes
3answers
59 views

GnuPG symmetric encryption yields different output

I have a use case where I want to commit symmetrically encrypted source code using GnuPG (think of Coursera assignments for backup and collaboration). I encrypt/decrypt all sources in a batch with a ...
5
votes
1answer
89 views

Master offline key, shared encryption/decryption key, unique signing keys?

I've read quite a few different articles on how to setup PGP keys with an offline master key. I own multiple YubiKey NEO hardware smart cards which I intend on using for PGP and as an SSH key. One of ...
0
votes
1answer
35 views

How to get my GNUPG Elgamal private key exponent?

I have tried googling around. The closest solution I get is: private.key contains the private key file. $pgpdump -i private.key But this only gives me the following: ElGamal p ElGamal g ElGamal y ...
1
vote
2answers
70 views

Can I specific a public key name instead of recipient when encrypt with GPG

Can I do something like: gpg --public-key my.pub -e file.txt If I can, any reason that I should not do that? P/s: I think I don't need to know about the recipient because on my machine have only ...
1
vote
1answer
39 views

Is it possible to convert a gpg key to a different encryption algorithm [duplicate]

Maybe the answer to this question is a simple and unequivocal "No", followed by "How can you possibly think that this is possible?". And if I think about it rationally this seems to be the only ...
2
votes
1answer
192 views

What is the default cipher algorithm for GnuPG?

I know, that one can force GnuPG to use AES256 for encryption with gpg --cipher-algo AES256 or with a special setting in ~/.gnu/gpg.conf. But, what is the default cypher algorithm for GnuPG, if I ...
3
votes
1answer
80 views

What public GPG key do I have to publish?

I just created a master key and two subkeys. The first subkey is used for encryption, the second one for signing. Now I am wondering what public key do I have to publish on my website. Does is ...
0
votes
1answer
104 views

How do I verify a GPG signature attached for a cleartext email using the gpg command line?

I received an email in cleartext from someone with a signature.asc attached. Looking at the raw source for the email, it was sent with Apple Mail + GPGMail. Reading the message in Thunderbird + ...
2
votes
1answer
168 views

PGP key on smart card: why do I need a “secret key” on disk?

I have a YubiKey NEO on which I have the OpenPGP applet and I have a PGP key installed. I work on 3 different computers and I initialized the card on computer bob. I'm now at computer rob. Someone ...
0
votes
1answer
188 views

How do I convert a GPG certificate to a CRT certificate that can be imported into Windows Certificate Manager?

I have a GPG certificate from someone used for email -----BEGIN PGP PUBLIC KEY BLOCK----- Version: GnuPG/MacGPG2 v2.0.14 (Darwin) I would like to import that into Windows Certificate Manager So ...
1
vote
0answers
48 views

OpenPGP (RFC4880) - do you agree with my SimpleS2K (string-to-key) implementation?

Background: I'm writing a GPL Python OpenPGP to JSON parser which I'm testing on files generated with GPG 1.4.16. If given a passphrase, the parser will generate keys using the string-to-key methods ...
2
votes
1answer
97 views

Short OpenPGP key IDs are insecure, how to configure GnuPG to use long key IDs instead?

Short OpenPGP key IDs (with 32 bits / 8 hex characters) are subject to collision attacks. It is strongly recommended to stop using 32 bit IDs: Stop using 32bit key ids It takes 4 seconds to ...
1
vote
1answer
38 views

Verify GnuPG download with signature file - and it fails

I'm trying to verify the new GnuPG download (for OS X) using GnuPG. (First of all I'm not sure if you should verify a file with the old version of it, which I probably didn't verify back then to be ...
1
vote
1answer
51 views

GPG: Detaching Public Subkeys - why can't I do it?

I understand the benefits of using subkeys. I also know that, in the case of private keys it is possible to detach the subkeys from the master key, since there are times when a user may prefer not to ...
8
votes
1answer
219 views

RSA key generation: gpg vs openssh

When I generate RSA key for ssh (both server-side and client-side): dpkg-reconfigure openssh-server ssh-keygen the key generation is completed instantly. However, when I generate RSA key for gpg, ...
3
votes
1answer
469 views

Why does GnuPG shrink my file after elgamal encryption?

I would like to run GnuPG elgamal encryption for at least a few minutes. The only way I can think of is to create a large file to be encrypted. So I created my file like this: dd if=/dev/zero ...
0
votes
0answers
141 views

“gpg” vs “openssl rsautl” (asymmetric keys) for credentials storage

I'm working in a PHP project and need a better solution to store credentials to a client's database, and I'm thinking about encryption, I put to work both gpg and openssl using asymmetric keys, but ...
3
votes
3answers
654 views

Sending an encrypted PGP email to someone who doesn't yet have my public key

Suppose I have the public key of a recipient I'd like to send an email to, and I've never sent this person an email before. Does it make sense to encrypt my first email to this recipient and also ...
3
votes
1answer
77 views

Ability to determine which PGP public keys a message has been encrypted for?

Is it possible to determine, given a PGP message that you can already decrypt, to determine which other PGP keys that message has also been encrypted for?