PGP is short for "Pretty Good Privacy". It is a data encryption and decryption computer program that provides cryptographic privacy and authentication for data communication. PGP is often used for signing, encrypting and decrypting texts, E-mails, files, directories and whole disk partitions to ...

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Secure self-concealing symmetric encryption (non-verifiable decryption)?

From what I observed using standard encryption tools such as OpenSSH and GPG, the decryption only succeeds when the correct password/key is provided (or at most a few others, in case of collision). ...
2
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1answer
248 views

Is it necessary to remove the primary secret GPG key from your laptop if it has full-disk encryption?

According to a number of articles, e.g. "Creating the Perfect GPG Keypair," it is advisable to have a number of subkeys in your GPG key, one for encryption, and one for signing, and then to (a) back ...
4
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2answers
196 views

How to properly transition from standard PGP keys to using subkeys?

When I initially set up PGP, PGPTools didn't prompt me to create separate subkeys, as explained in the article "Creating the Perfect PGP Keypair". Now that I've learned a bit more about PGP, I'd like ...
2
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3answers
199 views

GPG keys & SHA-1

I've heard that SHA-1 hashing is becoming less secure, and that most GPG keys are secured with SHA-1. Is there a way to determined if SHA-1 is in my GPG key, and what to do if this is the case?
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2answers
235 views

Does adding multiple recipients to an encrypted message decrease security?

Let's say you want to send the same GPG/OpenPGP encrypted message to 50+ recipients. Assuming everyone you send to is trusted, and there is no risk of any recipient leaking their secret key, is ...
2
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1answer
99 views

Which PGP settings have been found to be vulnerable?

Digging through articles, one often finds recommendations such as "Use the default key type/size X", whereas an article written a few years later will write "Key type/size X has been found to be ...
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1answer
349 views

GnuPG / OpenPGP: How to eliminate redundancy in PGP private key?

I examined a few randomly generated private keys generated by Gnu PG, and found a lot of redundancy. It is enclosed by -----BEGIN PGP PRIVATE KEY BLOCK----- and -----END PGP PRIVATE KEY BLOCK----- ...
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3answers
154 views

Adding a “comment” to PGP mail signature files?

I have started signing my mail with PGP, and it attaches the file signature.asc to my messages to verify that I sent them with content, as you'd expect, like this: -----BEGIN PGP SIGNATURE----- ...
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1answer
83 views

What happens if my signing subkeys are compromised?

Let's say my subkeys are compromised, but my master keypair is safe and secure, so I revoke the old subkeys and issue new ones. With encryption keys, the results are pretty clear: I can still decrypt ...
4
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1answer
197 views

How long do keys stay on keyservers?

Do GPG/PGP keyservers "garbage collect" old keys which have expired, been revoked, or simply haven't been updated in a decade? Or does the server (theoretically) keep every key it has ever seen from ...
3
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1answer
142 views

Will PGP signed email be blocked in China?

I generally sign all of my outgoing email with PGP. I don't usually encrypt it because most people I send mail to don't have a public key. Anyway, if I send an unencrypted message with a PGP signature ...
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3answers
165 views

What are you saying when you sign a PGP key?

When you sign a PGP/GPG key, what exactly are you saying to everyone who sees your signature? Are you validating the person, or the email address? To explain what I mean, take the following two ...
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3answers
3k views

Tell people that I can encrypt emails

I know that it is still not very easy to use PGP for an average user. However, the situation is improving (there are some easy plugins that can even nicely integrate into your GMail webmail). In ...
0
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2answers
109 views

Can I generate multiple PGP key pairs for later use

I was just wondering if I can generate couple of PGP key pairs and save them for later use or backup. In addition can I be sure that other wont generate and use some of my key pairs in the meantime. I ...
1
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3answers
195 views

How can an email sender include his PGP key, so I can answer with an encrypted mail?

Let's say I were to post my e-mail address and public PGP key to my website. When a client contacts me, they would have to include their PGP public key in the e-mail so that I can respond to them in ...
2
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2answers
71 views

Can the GPG master secret key be stored as read-only?

Once you have generated your master PGP key, will the "data" in the private key ever change? For instance, if you add another subkey, uid, or any other data to the master key, do these changes need ...
6
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3answers
212 views

Why can't PGP/GPG Web-of-Trust be automated?

We heard lots of complaints about hard to use crypto tools, and recent ideas of Google how to fix this. I had another idea about this which seems quite obvious, but couldn't find anything about it on ...
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1answer
898 views

Are SSH keys and PGP keys the same thing?

I have a 3072 bit RSA key that I generated for use with SSH. Can this key-pair be used with PGP/GPG, or do I need to generate a new pair of keys separately for use in email encryption? Are the two ...
2
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2answers
183 views

How can I secure my api to avoid copying?

Im building an app which should receive data from my server. The Api should be a PHP based script which provides the data as JSON. However I want to keep the data private and it should only be ...
3
votes
2answers
597 views

How to Conceal/Detect PGP Symmetric Algorithm Used

When Symmetrically encrypting a file, (not signing, not an asymmetric encryption question), is it possible to conceal the encryption algorithm used, or is it already concealed, but just showing on ...
0
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1answer
85 views

Keep OpenPGP revocation certificate in safe place?

Do I have to keep the revocation certificate of my OpenPGP key in a safe place or may I place it in e.g. Dropbox to have it ready on all my machines? I know that, if compromised, the certificate can ...
0
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2answers
197 views

Is there any reason to send file checksum for signed, encrypted files with MDC

I am using OpenPGP and sending a signed, encrypted file with forced MDC (Modification Detection Code) over the network. In typical file transfer scenarios where security is not in picture, an md5 ...
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3answers
320 views

Is PGP suitable for encrypting webservices?

I would like to know if I can use of PGP to ensure SOAP webservices confidentiality? I don't want use SSL, it's kind of slow mechanism to make a tunnel for high throughput data transaction. I though ...
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2answers
71 views

Attaching the same file to two separate email, does it compromise security of the “message”

When using (Thunderbird and) GnuPG to send a PGP/MIME message to two separate recipients, with the text body different in both messages, but the same file attached to both of them, does this give an ...
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2answers
258 views

PGP Encryption - Whats the need to encrypt using random one time key? [duplicate]

I just read about PGP encryption scheme here, and started wondering what is the need to encrypt the file with a one time random key? In other words, how is this scheme more secure than simply sending ...
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8answers
392 views

What are the benefits of encryption for everyday people?

In addition to the fact that encryption systems like PGP are notoriously difficult to use, and that encryption doesn't always jive with cloud-based services like webmail, the fact is that most people ...
30
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2answers
3k views

If I sign someone else's key and later decide it was a bad idea, is it possible to un-sign it?

Let's say that I sign someone's key and then later decide that was a bad idea - either it was a bad idea at all, or I should have signed it with a different level of trust. Is it possible, both in a ...
0
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1answer
393 views

Tor, PGP and Tor Entrance Nodes

Imagine alice posts her public PGP key on her website and bob encrypts a widget with that public key then sends it to alice over Tor. If alice's key is widely and publically available and an attacker ...
32
votes
2answers
2k views

Why does PGP work with the CC field in e-mails?

I was wondering how PGP works with a CC. In my understanding, if I send an e-mail to foo@example.com and use baz@example.org in the CC, Enigmail would have to encrypt the e-mail once for every user ...
2
votes
2answers
501 views

PGP/GPG verifying authenticity

My boss recently implemented a new security system related to PGP/GPG. The whole idea behind this is to sign files so that people know from who they came. They don't require us to encrypt them, just ...
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2answers
266 views

Password database vs flat encrypted file [closed]

I am considering putting a forward a proposal to use a password database/manager instead of a flat (PGP) encrypted file for managed passwords for our team to access. I would like to hear some ...
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4answers
1k views

Can I get a public key from PGP signature?

I have a PGP signature of a known message. However, I am not sure who signed it. Can I get the public key - or, at least, the fingerprint/other way of searching for it on a public keyserver - just ...
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3answers
730 views

Is storing the private key and public keys in same directory on server recommended, like OwnCloud does?

Is this recommended or a good/normal practice? I think not. Because I saw that OwnCloud stores all encryption keys in one directory on the server. One directory contains the private key(s) and one all ...
0
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1answer
69 views

What is “web of trust” in PGP and S-MIME? [duplicate]

I'm studying network and system security and I came across the phrase Web of Trust: In cryptography, a web of trust is a concept used in PGP, GnuPG, and other OpenPGP-compatible systems to ...
1
vote
3answers
485 views

What is the web of trust?

I'm studying network and system security and I came across the phrase "web of trust". From Wikipedia: In cryptography, a web of trust is a concept used in PGP, GnuPG, and other ...
2
votes
3answers
308 views

What does the pgp public key length depend on?

What does the pgp public key length depend on? Does a long private key result in a long public key? The longer public key the better; or is it even the private key the crucial factor?
1
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2answers
63 views

Is PGP web of trust exportable?

I know that in local PGP keyrings, there's an idea of trust: I trust this key ultimately, this key less than that, etc. Is this web-of-trust exportable? For example, if I trust someone@openssl.org ...
3
votes
1answer
46 views

Transferring of keys from key servers to recipients

When I download PGP keys from keyservers like so: gpg --search-keys steve@openssl.org How are the public keys transferred down to my machine? Is there a possibility of a MITM attack to serve me the ...
1
vote
1answer
319 views

GPG Different Passphrase for Subkey

Is it possible to have a different passphrase for a GPG subkey? The reason is that I'm using duplicity to back up my files, and it needs the key passphrase to sign the files. Since I want run ...
1
vote
1answer
277 views

How are private keys (sMIME, PGP, etc) synchronized across a user's devices?

Given that user needs to store a copy of the same private key on each of his devices (in order to decrypt email and other data encrypted with the public key) ... what are some general techniques for ...
5
votes
1answer
192 views

Should I sign the CAcert key?

Recently I got a CAcert Assurance and discovered that I can get my PGP key signed by CAcert key. After I got their signature, CAcert website suggested that I sign their key, too. Question: CAcert ...
6
votes
1answer
276 views

Recommended operational security for generating one's primary key pair?

I have been looking for an operational security guide for generating one's asymmetric key pair for (Open)PGP. I have found plenty of technical guides for how to use GnuPG to generate RSA key-pairs, ...
6
votes
4answers
416 views

Establishing a Reputable Pseudonym with PGP Key

This has become a bit of a thought experiment for me. Suppose someone would like to establish a pseudonym along with a corresponding PGP Key, how could other people verify the correspondence between ...
2
votes
1answer
139 views

Why do I have keys of strangers in my GPG keychain?

I'm going though my GPG keychain. I've got a key for a few strangers in my keychain. I don't recall exchanging keys and I'm not sure how the public keys came to be installed in the keychain. I think ...
3
votes
1answer
186 views

Utility of multiple signing subkeys when we're restricted to a single encryption subkey in GnuPG (PGP)

As I understand it, GnuPG allows the creation of multiple subkeys, but multiple encryption subkeys are problematic because it's not clear which encryption subkey someone should use when sending a ...
2
votes
2answers
336 views

PGP as method of sharing AES key?

Would PGP work as a method of sharing the AES key, as shown below, and what would be the flaws with this method of encryption? Server sends PGP public key Client generates (uses as AES key for ...
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1answer
98 views

How to validate the confirmation link received when publishing a new PGP key?

I find PGP to be quite a complex subject. I have gotten to a point where I need to give a client a public key for encryption. I have successfully done my homework, generating a public key from my ...
4
votes
1answer
427 views

GPG master key without email address

I would like to create a new GPG key. Going through a couple of thread it seems like the most popular scheme for maximum security is to have an offsite master (sign-only) key which provides a shell ...
4
votes
1answer
283 views

How are PGP/GPG private keys stored?

The default format in which SSH private keys are stored is notably fairly insecure against bruteforce attacks. This question provides a very nice solution to the problem by encrypting SSH private keys ...
3
votes
4answers
451 views

Does a PGP signature provide integrity verification?

Many websites including OpenSSL's website provide downloads along with MD5/SHA1 checksums sometimes in addition to PGP signatures for the files. Simply put, do PGP signatures provide file integrity ...