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

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Can I expose a passphrase-protected private OpenPGP key?

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 ...
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1answer
26 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
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1answer
20 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 ...
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1answer
18 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 ...
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1answer
23 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 ...
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1answer
21 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
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1answer
33 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.
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1answer
24 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 ...
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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 ...
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13 views

GPG: Create a “second” key for office email address [migrated]

so I have created an RSA PGP key using gpg --gen-key. I added more private email addresses to this key using gpg --edit-key MYKEY. The problem: I have an office email address, which I only use from ...
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1answer
21 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). ...
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0answers
56 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, ...
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5answers
161 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
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1answer
24 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
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1answer
29 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 ...
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0answers
52 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
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1answer
24 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 ...
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1answer
24 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 ...
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2answers
42 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 ...
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1answer
50 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
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1answer
146 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
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1answer
37 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
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1answer
49 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
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1answer
67 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
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1answer
107 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 ...
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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 ...
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2answers
38 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 ...
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3answers
57 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
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1answer
72 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
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1answer
28 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 ...
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2answers
51 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 ...
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1answer
38 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
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1answer
110 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 ...
0
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1answer
67 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
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1answer
135 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
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1answer
156 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 ...
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0answers
40 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
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1answer
79 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 ...
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1answer
36 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 ...
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1answer
47 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
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1answer
181 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
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1answer
464 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
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0answers
129 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 ...
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3answers
494 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
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1answer
73 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?
0
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1answer
85 views

Change the preferred algorythm from AES to Camellia in an existing PGP key [duplicate]

I already created a PGP key-pair in Thunderbird Enigmail on Ubuntu. Now I would like to change the key, so it uses preferably Camellia-256 for encryption. How can I change the preferred algorithm ...
4
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2answers
469 views

When signing email with GPG, how does verification by the receiver work?

I use GPG to sign my outgoing emails. I understand how it works when I encrypt mail to send to someone else. Then I need his/her public key, encrypt it with that, and only he can decrypt it using ...
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2answers
427 views

How to change default cipher in GnuPG on both Linux and Windows?

How can I change the default symmetric cipher used by GnuPG from CAST5 to another? I'm using GPG4Win on Windows, but would also be interested in a solution for Linux.
2
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1answer
73 views

If OpenPGP insecure if it only supports PCKS#1 v1.5?

I've just read the RFC 4880 specs and there is nothing about OAEP; only PKCS#1 v1.5. If it is true that the OpenPGP-standard only supports the PKCS#1 v1.5 padding-scheme, is this a security issue? ...
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1answer
202 views

How do PGP keyservers synchronize the keys?

I want to know technical details about how public PGP keyservers synchronize the keys. If I send my key to one keyserver, how exactly does it "travel" to all the other ones? Who sends it to who and ...