Questions tagged [pgp]
The OpenPGP encrypted data format (RFC 4880), and its implementations PGP and GnuPG.
240
questions
0
votes
0
answers
11
views
How to import OpenPGP Card / YubiKey backup encryption key [migrated]
When I generate a new OpenPGP key on a YubiKey, it gives me the option to save a copy of the encryption key as a backup like so:
...
- 101
0
votes
0
answers
16
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
1
vote
0
answers
25
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
27
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?
- 51
1
vote
1
answer
37
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, ...
- 51
2
votes
0
answers
32
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
78
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 ...
- 21
0
votes
1
answer
52
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 ...
- 51
1
vote
0
answers
35
views
1
vote
1
answer
41
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
1
vote
0
answers
40
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-...
- 51
2
votes
2
answers
377
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 ...
- 25
0
votes
2
answers
50
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
105
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 ...
- 143
1
vote
1
answer
107
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 ...
- 45
0
votes
1
answer
77
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
152
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
108
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
84
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
42
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 ...
- 595
0
votes
0
answers
50
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
3k
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 ...
- 173
1
vote
1
answer
356
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? ...
- 13
3
votes
1
answer
159
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 ...
- 12.9k
1
vote
0
answers
25
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 ...
- 127
0
votes
0
answers
42
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
475
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
189
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 ...
- 117
1
vote
1
answer
777
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 ...
- 165
6
votes
1
answer
1k
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 ...
-1
votes
1
answer
371
views
2
votes
0
answers
139
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 ...
0
votes
1
answer
136
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
243
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
134
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
142
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
100
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
314
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
445
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
192
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
238
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
1
vote
2
answers
681
views
What is the PGP Web of Trust Strongset?
I understand that it is a system that "establishes the authenticity of the binding between public keys and their owners", but how does one join this web of trust? Do you have to physically meet one of ...
- 407
2
votes
1
answer
159
views
Encrypt text message with Wireguard public key
With its public and private key(s), Wireguard looks a bit like PGP. But it is used for encryption of network packets and not normal text messages. I'm on a system with Wireguard already installed and ...
- 21
1
vote
1
answer
217
views
What prevents ProtonMail from sending me the wrong public keys?
I've recently been looking at ProtonMail, an email service which provides transparent end to end encryption between users with PGP. In order for the encryption to be transparent, ProtonMail manages ...
- 163
1
vote
2
answers
149
views
Is it possible to verify a clearsigned message with a short public key (fingerprints)?
For practical reasons, I'd like people to be able to post clearsigned messages with their public key fingerprints (8E570D9F7F70256595769E49F9BC5BCAD7E18635) for the ...
- 113
3
votes
1
answer
2k
views
What does Modification Detection Code (MDC) in OpenPGP do?
The authentication is often done by an HMAC in modern cryptosystems. What does MDC do exactly in OpenPGP and is it a software hack or an algorithmic authentication?
Also, how to force GnuPG to stop ...
- 133
0
votes
1
answer
89
views
why Efail CFB malleability gadget is different from CFB mode decryption?
Really, I could not understand why the decryption process of CFB malleability gadget takes the next cipher block while PGP uses the previous block as shown in the equations in the attached image, I ...
Sam2050
1
vote
1
answer
601
views
Testing speed of symmetric vs asymmetric encryption and decryption using gpg
I'm aware that symmetric is faster than asymmetric.
I want to test this, but my (obviously incorrect) tests show the reverse.
Symmetric test:
...
- 147
1
vote
1
answer
272
views
Encrypt symmetric session key with asymmetric or symmetric master key?
Every day, I must backup my server's files, encrypt the backup, and upload it to untrusted cloud storage (dropbox, s3, etc.)
I've spent time on security.stackexchange where I discovered the typical ...
- 147
1
vote
1
answer
117
views
Creating nested messages in OpenPGP
I need to create a nested message in OpenPGP (my understanding is that the protocol itself should support it).
Let's say I have Payload ("Time in Lordran is ...
