WEBVTT

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Let's talk about distributing the keys! Someone's public key is needed when you want to send that person

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an encrypted message

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or to check the digital signature of the key owner.

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Ideally you distribute your public key by personally giving it to your correspondents.

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In practice, however, keys are often distributed by email which is good practice

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when you have only a few correspondents.

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But if you have many correspondents it's easier to post your public key on a Web site.

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This is unacceptable however if people who need your public key do not know where to find it on the

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web. To solve this problem

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Public Key servers are used to collect and distribute public keys. A public key received by this server

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is added to the servers database

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and when a key request comes to the server the server  consults its database and returns the requested

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Public Key if found.

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Let’s see how it works. Imagine you've just downloaded the Centos ISO and a digital signature files and

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you want to check the signature. To do that

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you need the public signing key of Centos

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and on the official website you've found out its id. Your next logical step is to import the key with

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that id from a key server; and by execute the gpg--key server the name of the key server 

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pgp.mit.edu--recv from receive and the key id;  found the key id

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on the Centos Web site; perfect.

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The public signing key of Centos was imported in the keyring

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It's in the keyring.

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Now if you want to publish your public key on a key server, where everyone can find it, you simply execute

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gpg--keyserver

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hkp:// and the domain of the key server pgp.mit.edu --

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send-keys and the key id.

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Let's see in another terminal what's the key id

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this is my key id;  copy and paste here.

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Okay sorry, 

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there is a mistake, 

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the name of the key server is pgp.mit.edu

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not gpg

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This is its name; my public key was published on the key server pgp.mit.edu is one of the

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most used public key servers in the world.

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There are also other public key servers and most of them belong to a pool of key servers that gets synchronized.

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That means that when you publish your key on a server, after a while, the key will be automatically copied

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on all other servers in the pool and the request to any of the servers will get the key.

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Note that there is also a graphical interface that can be used to submit a new public key or to search

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for an existing key using its id; pgp.mit.edu and I can paste here

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my public key id; the id of the key I've just submitted

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and the key is already on the server.

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Let's see the key.

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This is the public key.

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I want to check that's the same key that is stored locally

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let's list the key

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so gpg --export -- armor and the key id.

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Okay.

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This is the public key

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and we notice it's the same key.

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Here in the search box

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don't forget to prefix the key id with 0x, which comes from hexadecimal. That's all about the gpg key

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management

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for the moment.

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Thank you.