Questions tagged [pgp]
The OpenPGP encrypted data format (RFC 4880), and its implementations PGP and GnuPG.
249
questions
1
vote
0
answers
54
views
Cannot protect GPG key using TPM2 on Ubuntu 22.04
I'm trying to protect a GPG key using the TPM2 available on my laptop, but I'm not having any success. Probably I'm doing something wrong, but I cannot figure out what this is.
My system is running <...
- 181
0
votes
1
answer
97
views
How secure is a file encrypted with GnuPG, a strong passphrase, and the symmetric option?
Suppose I encrypt a file, of, say, 10 MB, with a secure, suitable passphrase, and the command:
gpg --symmetric my_file.txt
What level of expertise and hardware ...
0
votes
1
answer
266
views
Kleopatra: What is the strongest and most popular cryptography standard for PGP
While setting up PGP for the first time, I am presented with various encryption standards I can use being:
RSA (2048, 3072, 4096 bits) with an option for + RSA (2048, 3072, 4096 bits)
DSA (2048 bits) ...
- 1
4
votes
1
answer
397
views
Where does signing/decrypting take place on a YubiKey 5 for PGP private key?
I have found similar question for PIV (and not PGP)
I assume PIV and OpenPGP would work in similar ways. I also assumes that the GPG private key never leaves the Yubikey.
If these assumptions are ...
- 43
1
vote
1
answer
199
views
Correct terminology for ECC in PGP
These days I'm generating some PGP keypairs, and I'm struggling to understand the correct terminology behind ECC keys. Moslty in the differences between ed25519/<...
- 113
1
vote
1
answer
76
views
Understanding symmetric encryption security in relation to password-based key derivation
Here are some assumptions on which the question is based. If anything is wrong with this, please point this out straight away:
Let's say I have a file I want to encrypt with AES256 symmetric ...
- 13
3
votes
0
answers
157
views
Multiple signature encryption with GnuPG
I'm aware that GnuPG encrypts for multiple recipients, but is there any way to build a multisig, say, 2 of 5 signatures with GPG?
So having a file encrypted for the following recipients needs at least ...
- 31
1
vote
1
answer
30
views
OPGP: tag8 being converted to tag11, part of 4880 spec?
When a tag8 compressed data packet does not contain compressed data i've seen some products simply handle the packet as a tag11 literal data packet, yet i find nothing in the 4880 spec old/new ...
- 11
3
votes
1
answer
219
views
Is the signature in PGP compressed as well, or just the contents of the message?
I am developing an implementation of OpenPGP, and I'm using Kleopatra to test my generated messages.
After generating a signature for a message, I compress both the message and signature, but upon ...
- 63
0
votes
1
answer
448
views
GnuPG - provide encryption key for AES rather than deriving it from passphrase
I'd like to encrypt a file with AES256 and provide my own 32-bytes for the encryption, rather than having GPG derive it from the passphrase.
I could not find such option, but I'm thinking about a ...
0
votes
0
answers
39
views
What, if any, are the IETF namespace notations for OpenPGP signatures?
RFC 4880 section 5.2.3.16, "Notation Data," describes how arbitrary additional notations in the form of name-value pairs can be included in an OpenPGP signature packet. Regarding names, it ...
- 101
2
votes
0
answers
40
views
Can you derive the public key from a PGP encrypted message without knowing the message content?
I am working on a system to transfer short messages while obfuscating the intended recipient.
In essence, it combines many messages encrypted using PGP, and periodically publishes a file containing ...
0
votes
0
answers
36
views
Only DRBG is used for PGP or could use other PRNG?
-RFC4880 refer to DRBG at https://www.rfc-editor.org/rfc/rfc4880#section-16.2
-Could we apply other PRNG such as enocoro/photon for pgp?
- 61
1
vote
1
answer
129
views
MAC vs MDC when using ECDH+ECDSA in OpenPGP
I intend to design a model to comply with RFC4880.
According to RFC6637, ECC in OpenPGP
+ECDSA to sign message
+ECDH + KeyWrap for session key encryption
-MAC: is used for key confirmation (with C(1e, ...
- 61
2
votes
0
answers
51
views
Is it possible to use PGP subkeys in multiple emails without correlating them?
I would like to know if sub-public keys of PGP keys can be published separately, if I create a pair of master keys and multiple sub keys to be used in multiple emails, and normally use only the sub ...
- 21
1
vote
0
answers
110
views
Web of trust assigning level of trust to someone's public key without directly signing it's key
Having this web of trust scheme, I have a question concerning third scenario in which we assign Dharma and Chloe a marginal trust. In case of Dharma the situation is clear, we sign her public key and ...
- 53
0
votes
1
answer
345
views
RSA Encryption and ECDH in OpenPGP
According to RFC4880 standard
1.Refer to section 2.1 Confidentiality via Encryption --> OpenPGP combines symmetric-key encryption and public-key encryption to provide confidentiality
+To protect ...
- 61
1
vote
0
answers
717
views
1
vote
1
answer
119
views
Is gpg -c safe if an attacker can see multiple versions of a file?
Let's say I have a text file, and I modify it slightly 20 times, and I encrypt each modification using gpg -c (with the same 20 chars secure password). If the attacker has access to the 20 encrypted ...
- 11
2
votes
0
answers
85
views
Can other modes be applied in OpenPGP (not using CFB mode)?
According to https://www.rfc-editor.org/rfc/rfc4880.html#section-13.9
-> OpenPGP only mentioned about CFB mode.
According to https://csrc.nist.gov/CSRC/media/projects/cryptographic-module-...
- 61
4
votes
2
answers
5k
views
How do you get a Public Key from a Fingerprint
I've seen some people putting their public key's (I'd suppose they refer to a PGP PK) fingerprint on powerpoints and alike so that they can be reached out to using a safe channel.
From my POV, it's ...
- 45
0
votes
2
answers
97
views
DKIM &PGP email security
I'm trying to figure out when using DKIM it signs all of the email including the body message and the from address , and with pgp it uses a unique key while in dkim is a general key ... but with both ...
1
vote
1
answer
478
views
Are PGP messages susceptible to man-in-the-middle attack?
Say Alice wants to send a PGP encrypted message to Bob.
She generates a symmetric key, encrypts it with Bob's public key, and sends both the message and the encrypted symmetric key to Bob.
Then Bob is ...
- 153
2
votes
1
answer
419
views
Which elliptic curve was used by Thunderbird OpenPGP and which bitlength?
If one looks at Account Settings > End-to-End-Encryption > Add Key and creates a new key then gets the option EC. But you can't choose the bit length nor does ...
- 55
0
votes
1
answer
121
views
Pretty much confused about pretty good privacy-:
Authentication-:
I understand that authentication is basically digital signature. But what I don't understand is how it has been explained here specially the RSA key part. It is leading me to huge ...
- 1
2
votes
2
answers
2k
views
Why do people use protocols like PGP, when TLS already exists?
TLS is the standard cryptography protocol on the internet, and many websites use it to secure their communications. However, for personal use, most people use other protocols like PGP, instead of ...
1
vote
2
answers
279
views
Can I use SHA256 from BIP39 passphrase for auth credentials?
I am working on an E2E encrypted app. I am using OpenPGP.js and storing public and private keys on the server. The private key is encrypted with a BIP39 passphrase which is stored in browser ...
1
vote
1
answer
104
views
Multiuser encryption, singleuser decryption [duplicate]
I have an hybrid encryption (RSA, AES) for a file sharing project I am working on, where I use a single public key for encryption on the sender side and corresponding private key for decryption on the ...
- 13
1
vote
0
answers
67
views
Should strong RSA key with SHA1 self-signature in public key to be considered weak?
Older RSA-4096 GPG keys generated when SHA1 still thought to be acceptable have public key self-signed with SHA1. Shall this considered to be weak key? And with what arguments? AFAIK, GPG key ids are ...
- 625
0
votes
0
answers
54
views
Saving highly sensitive data in US cloud - what encryption would you use?
We have a cloud-based application running on AWS servers and are looking for a way to store highly sensitive user data there without giving AWS the possibility of exposing our data to the US ...
- 1
7
votes
1
answer
5k
views
Why are NIST curves still used?
I'm relatively new to the world of crypto (But as far as the math goes, I am familiar with the inner workings. I used to rarely use it for privacy, but now I use it for many things).
Anyway, I was ...
- 243
2
votes
1
answer
2k
views
Why use ASCII armor for file encryption?
GPG and age both offer a --armor option but what is the use case when it comes to file encryption? Surely most channels allow for transmitting binary data nowadays? ...
- 23
3
votes
1
answer
172
views
How many encryptions are needed before OpenPGP key privacy is violated?
According to an excellent answer describing the pitfalls of key privacy in OpenPGP:
Theoretically, an all-zero key ID can be used as a way to discourage traffic analysis, but this is not a complete ...
- 15.1k
1
vote
0
answers
26
views
PGP files included on email [closed]
I just got an email from a professor that included two files, with no clues about them in the message. The files are named OpenPGP_...EA.asc and OpenPGP_signature. I figured, since I asked some stuff ...
- 187
0
votes
0
answers
51
views
Add setup to GPG symmetric
I use GPG symmetric, to encrypt text file.
Is it possible to use GPG symmetric, to encrypt a text file, and at the same time, add additional setting to the encrypted file, to give us 2 conditions:
...
- 1
0
votes
0
answers
2k
views
PGP file size limit for encryption
Unsure it's the best place to ask, anyway:
I know symmetric encryption is the best for such tasks but I am planning to encrypt large backup files (between 10 and 100GB) with my private PGP key. My ...
- 35
4
votes
1
answer
287
views
Why does PGP still use the Fermat primality test? What if it hits one of the Carmichael numbers？
Since the Fermat primality test is not very reliable, most applications use it for pretesting only. Wikipedia says that PGP still uses it:
Another well known program that relies only on the Fermat ...
- 159
1
vote
1
answer
2k
views
Is GPG symmetric encryption only based on a passphrase?
Is the symmetric key derived for AES only dependent on the passphrase?
Is it possible to generate the encryption key such that it is based on my primary GPG private key and temporary passphrase? In ...
- 175
7
votes
1
answer
2k
views
How is the session key more secure than the public key?
From the website of GNU Privacy Guard (GnuPG):
If an attacker could decrypt a session key it would only be useful for reading the one message encrypted with that session key. The attacker would have ...
- 101
-1
votes
1
answer
2k
views
2
votes
0
answers
241
views
GPG should you double sign?
This is not a question about whether I should encrypt or sign first, as I've read here.
Rather, it's about whether I should sign, then encrypt, then sign again.
Because as far as I know, there is no ...
- 101
0
votes
1
answer
610
views
How to correctly (good practice) generate gpg keys in batch mode (unattended) WITH a passphrase
I'm writing a web interface in PHP to generate keys. I'm familiar with gpg's command line options, particularly --batch. I'm also familiar with PHP's GnuPG API.
I can't find a way to safely pass the ...
2
votes
1
answer
402
views
PGP signature on literal data packet
I read from PGP spec RFC 1991, section 6.1 (August 1996):
The exclusion of the other fields ensures that detached signatures are exactly the same as attached signatures prefixed to the message. ...
0
votes
0
answers
283
views
Can there be different representation of the same public PGP key?
I have two PGP public key files:
File1 was created with Kleopatra / Gpg4win.
File2 was created by the following procedure:
Import File1 as public key for EmailAccount1 into Thunderbird 78.4.0
Send ...
0
votes
0
answers
259
views
GPG + OTP--Would that be authenticated encryption?
Here is a GPG message, signed and encrypted (strictly for demonstration, with test keys):
...
- 1
1
vote
1
answer
315
views
Authenticated, Quantum-resistant GPG2?
GPG2 does not provide authentication. It still uses SHA-1 by default. It does not seem to get any stronger as time goes by.
If one were to pass a randomly-generated symmetric key (from a TRNG) over ...
- 11
3
votes
1
answer
456
views
Signing a GPG Public Key
I am trying to manually create a GPG Public Key (see here). I am able to generate a GPG Public Key with a correct hash, but fail to RSA-sign that hash in a way that is accepted by the GPG CLI. For the ...
- 193
2
votes
1
answer
1k
views
Is it possible to get the PGP public key from PGP message?
Is it possible to get the public key from PGP message in PEM(Base64) format? Here is the message:
...
- 21
3
votes
1
answer
284
views
Manually creating a GPG Public Key
I want to manually create a GPG public key that can be imported into GPG, i.e. I want to create a file with a Public-Key Packet, a User ID Packet and a Signature Packet (for an example see here). I ...
- 193
2
votes
1
answer
477
views
Why is GnuPG changing first two characters of ascii armored public key after downloading it from the key server?
When I look at my public key on the key server, the first two characters of the ASCII-Armored data section (as defined in section 6.2 of RFC 4880, which defines the structure of the ASCII-Armored ...
- 121