Public-key cryptography (encryption is a misnomer) is the process of creating two keys during the encryption of plain text, one private and one public.

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101
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How can I use encryption with Gmail?

I'm currently reading Cory Doctorow's novel Little Brother which includes a part about encrypted messaging, and even wrapping messages first in my private key and then your public key. I'd like to ...
30
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5answers
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How does SSH encryption work?

I've read about generating 2 keys (private and public) on client host and copying the public key to the server host. As I understand it, (correct me if i'm wrong): The server encrypts data with the ...
19
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1answer
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Does the right half of the rsa public key matter?

In a public key file "id_rsa.pub" generated by ssh-keygen, does the part after the == matter? I ask because when I changed "root@somedomain.com" to "root", it seems to still work. More generally, I ...
13
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2answers
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How, if at all, do SSH keys differ from asymmetric keys used for other purposes?

How, if at all, do SSH keys differ from asymmetric keys used for other purposes, e.g. email signing? I'm prompted to ask this, in part, because on OS X, there are apps available to manage SSH keys ...
12
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3answers
4k views

Why does GPG/PGP by default use different keys for signing/encryption?

If you create a new GPG key, you'll by default get a signing-only master key pair and an encryption-only sub-key pair. pub 2048R/XXXXXXXX created: 2013-02-09 expires: 2014-02-09 usage: SC sec ...
11
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3answers
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Human-readable dump of gpg public key

Is there some tool to write out the actual content of a GnuPG public key in a way a human can unserstand? I mean not only ascii-armor which a human can read and type, but something which really breaks ...
10
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2answers
804 views

How are public keys “sent” to servers, and how are private keys “used” for SSH?

There are two Linux machines, A and B. Scripts running on A need to be able to SSH into B. So A generates a public key (probably an ssh-keygen-generated id_rsa.pub), and then uses its respective ...
8
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5answers
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How to generate a public/private key (UNIX)

Can some one please tell me, for using SSH, why does a host also need to have a public and private key? And how can I generate a public/private key pair for myself?
8
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1answer
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Can I change the filename of my ssh public/private key pair?

I created a public/private key pair: ssh-keygen -t rsa -C "me@example.com" I gave a different key file name than id_rsa since I wanted to create a new separate key from my normal identity. I gave ...
7
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2answers
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Isn't it dangerous to use SSH keys to login to an unknown/compromised server?

Say I provide someone with my public SSH key, the id_rsa.pub and he/she installs it on a server that is compromised, and I am asked to login. Does the login process involve sending my private key to ...
7
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2answers
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How can I use GnuPG with ECDSA keys?

I'd like to generate an ECDSA (rather than RSA, DSA, or ElGamal) key using GnuPG, and use it as I might otherwise use an OpenPGP-compatible master key. I've read that gpg2has support for ECDSA keys, ...
5
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3answers
107 views

How does public/private key cryptography work, who generates the key pair?

I have a requirement to encrypt a file, get it to an external partner who will then decrypt the file using a key. My "basic" understanding is that I can generate the public and private keys, encode ...
5
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1answer
251 views

Is uploading your openssh public key to ~/.ssh/ for a given user safe?

I like to upload my public key (eg: ~/.ssh/id_rsa.pub) to various servers that I connect to on various networks for work. I use this same public key on Github. If I am on a shared user account and I ...
5
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2answers
1k views

how to verify the trust path to a gpg key?

I want to check whether the gpg key used by Julien Danjou for his emacs snapshot repository can be trusted. There are many trust paths from my key to Juliens key. But I can't believe that there ...
5
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2answers
465 views

How can I get a new / non-technical user to verify my GnuPG / PGP signed email?

I'm looking for a web front-end or some easy way to get a user who's never been exposed to cryptography / digital signatures etc. to simply copy/paste my GPG signed (not encrypted) email and specify ...
4
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2answers
227 views

When I encrypt a message with my public key, can I read it with the same public key?

On a process that is using asymmetric encryption(such as ssh), when I want to send a message to someone using my public key, can I decrypt and read this message with my public key (the same that I ...
4
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1answer
4k views

How to setup ssh, key-based (“password-less”) logins to a Linux/MacOSX sshd server via Windows, Linux, or MacOSX clients?

How does one setup ssh, key-based ("password-less") client logins to a Linux/MacOSX sshd server via Windows, Linux, or MacOSX clients? [Seeking both basic, conceptual understanding of key-based, ...
4
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1answer
3k views

Setting up sshd_config in cygwin for AES encrypted file transfer

I'm a bit newer to cygwin and sshd, and I want to configure sshd to allow encrypted SFTP file transferring. From what I understand, I need to find some sort of sshd_config example (which for some ...
3
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1answer
1k views

How to ASCII-armor my public key without installing GPG?

I would like to upload my public key to a key server, but I already have my key infrastructure in place without GPG and I don't want to install extra software I don't need. Is there an easy way to ...
3
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2answers
55 views

Why does PGP encrypt differently when piping into a file instead of printing the result?

I'll use the following PGP key stored in pub.pem: -----BEGIN PGP PUBLIC KEY BLOCK----- Version: PGPfreeware 6.5.8 for non-commercial use <http://www.pgp.com> ...
3
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1answer
45 views

Should my OpenPGP key used for storing documents in the cloud expire?

I plan on doing a mass migration of all my local files to various cloud services since space is pretty cheap these days. I figure I should probably encrypt my data before I upload it, which is better ...
3
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2answers
16k views

sftp and public keys

I am trying to sftp into an a server hosted by someone else. To make sure this worked I did the standard sftp user@sftp.xxxxxx.com i was promted with the password and that worked fine. I am setting ...
3
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0answers
210 views

Is there a tool like dm-crypt/luks using RSA encryption?

Is there a library/tool available for linux, similar to dm-crypt/LUKS using RSA encryption instead of symmetric ciphers? I want the "public side" to only be able to create these volumes, and the ...
3
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0answers
470 views

How to decrypt a message sent via Pidgin-Encryption?

A friend sent me an offline Google Talk message that was encrypted via Pidgin-Encryption. It didn't appear in my Pidgin logs because I wasn't logged in when it was sent, but I do have the encrypted ...
2
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4answers
859 views

Encrypt tar file asymmetrically

I want to achieve something like tar -c directory | openssl foo > encrypted_tarfile.dat I need the openssl tool to use public key encryption. I found an earlier question about symmetric ...
2
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1answer
2k views

Can you extend the expiration date of an already expired GPG key?

Lets say I add an expiration date to a GPG/PGP key, then for some reason am unable to extend the expiration date of the key before its time is up. Assuming I still have access to the private key (and ...
2
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2answers
636 views

SSH Using Wrong ID

I am trying to establish password-less ssh to myself on a CentOS6 system. I go through the following steps: ssh-keygen -t dsa -P '' -f ~/.ssh/id_dsa cat ~/.ssh/id_dsa.pub >> ...
2
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1answer
99 views

Does Key based authentication replace or rather supplement password authentication?

Is SSH key based authentication something that happens to replace password authentication or does it supplement password authentication?
2
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1answer
167 views

Why am I prompted for a password when using SSH to connect to another server?

I installed a fresh copy of CentOS 6.4 on two boxes, and Im trying to setup password-less SSH from server1 to server2. On server 1, I generated a key with ssh-keygen, transferred it to server2, put ...
2
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1answer
1k views

gpg: import failure key xxxxxxxx: no valid user IDs

i am getting this error while importing a public key on gpg (GnuPG) 1.4.2 gpg: armor header: Version: GnuPG v2.0.14 (GNU/Linux) gpg: pub xxxxx/xxxxxxxx 2012-05-25 abcd xyz <email@address.com> ...
2
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0answers
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Duplicati uses symmetric encryption despite giving the recipient ID_key

I have a question regarding decrypt using gpg asymmetrically. I use duplicity encrypt copies asymmetrically. E.g: `Duplicati.CommandLine.exe backup s3://testduplicatigpg3 C:\Users\test\Desktop\tt ...
2
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0answers
76 views

How can I allow a user to connect to my OpenVPN by knowing their public key?

Given the public key of a remote user, I would like to run OpenVPN and allow that user to connect to my network. I only need to be connected to one remote machine at a time. The options outlined in ...
1
vote
1answer
2k views

How does gpg handle multiple keys in a keypair?

As I understand it, keypairs used with gpg generally have more than one associated key: one for signing and one for encryption. How are these multiple keys managed when using gpg (to push to a ...
1
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3answers
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How to get GPG working with Outlook 2013?

My OS is Windows 8.1 Update 1 x64. I have Outlook 2013 and just installed GPG4Win (latest, 2.2.2, full version). When I now launch Outlook 2013, I still don't see any UI/options to setup certificates ...
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1answer
2k views

What is the role of cakey.pem and cacert.pem in addition to .key and .crt based encryption

I have .key file which holds the private key data, .crt file which would be certificate with public key and, to my knowledge, that's it for public key encryption, right? Not exactly. In order to ...
1
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1answer
75 views

Creating encrypted database for work

My boss posed this problem to me: Encrypted: We need an encrypted database for miscellanious passwords we use at work that are currently only in people's head. Easily accessable: Someone needs to be ...
1
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1answer
4k views

How to recover files from infected. Vvv extention [duplicate]

Can any one help for how can remove this virus. Our all computer's files infected from this (.vvv) virus. We are using windows 7 Plz give me strong methods. If you need remote screen i will provide ...
1
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1answer
651 views

Outlook missing “Publish to GAL”

Unable to encrypt emails with valid certificates in exchange environment. I just thought of publishing the public keys to GAL but Publish to GAL option is missing Things i've tried : Re-download ...
1
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2answers
3k views

Configuring Public Key Authentication with SSHD under Cygwin

I am trying to configure SSHD to allow public key authentication under Cygwin on Windows Server 2012. Currently my problem is access being denied. I have confirmed that my public key is saved as a ...
1
vote
1answer
766 views

Signature Verification using OpenSSL

I have been experimenting with OpenSSL and OpenSSH and I have been unable to sign and verify using RSA key pairs. I did the following Generated key pairs: $ ssh-genkey -b 2048 -t rsa ...
1
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1answer
82 views

OpenSSH client refuses to use a new key file

After generating a new ssh private key (id_rsa) on one server and distributing it across a server network, one server is failing to use the new key, and falls back to password authentication instead. ...
1
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2answers
402 views

How do you create an AES XTS key?

I am interested in hacking around with Gluster cloud FS whose most recent beta uses AES with XTS only. It also requires openssl >= 1.0.1. The 1.0.1f Jan 2014 openssl (with 64 bit lib) install for my ...
1
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1answer
113 views

Finding sshd log file

I'm experiencing some problems with SSHD on my server. I'm trying to set up passwordless (pub/pv keys) authentication. It worked for my other servers, but not for this one. The SSHD agent adds my ...
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0answers
201 views

SSH keys cached remotely?

I wanted to install a new public key on a remote server. I created a keypair using ssh-keygen -t rsa on my Macbook, then added its public key to authorized_keys on the remote server. It is the only ...
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1answer
199 views

SSH rsa key works with external IP not internal IP

I am using rackspace cloud hosting. I have 2 servers behind a load balancer. Each server has an external IP and an internal IP. I want to setup a sync job that uses SSH to transfer files. I made ...
0
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2answers
280 views

Can a client server host multiple private ssh key for same profile?

I have a client who is using Tectia Client to connect to our UAT. They created a ssh pair and imported the private key to the profile they are using to connect,and passed us the public key. Now we ...
0
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3answers
485 views

Is there a way to revoke a GPG encryption key?

OK, so as I understand it, the key revocation mechanism is used to revoke a signing key in your web of trust: so you say to other GPG users that your previously-used identity has been compromised, and ...
0
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1answer
51 views

Why would one want to tag the computer where a key pair was made in a public key?

While trying to give an host a bit more of security, i decided to switch to SSH key's authentication. To do so i followed this guide, but something makes no sense in my mind. While the host is the ...
0
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1answer
317 views

How to embed an ASCII logo into an ASCII-armored RSA key?

The cryptoparty site publishes an RSA key with an ASCII art logo embedded in it. Is there a way to put arbitrary characters in an ASCII-armored RSA key? From https://github.com/cryptoparty/handbook ...
0
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1answer
1k views

Using Windows 7, is there any way to create a self-signed public/private key pair for email?

Is there any way for me to create my own certificate pair? I don't see why I would need a trusted CA for email purposes. I'd rather a cert than using GPG or something of the like.