Key Escrow – CompTIA Security+ SY0-401: 6.1

In large environments, your encryption keys may be held by a third-party to ensure that the encrypted data can always be recovered. In this video, you’ll learn about key escrow and some of the business cases where key escrow should be used.

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When we talk about escrow we’re talking about a third party that’s holding something for us. This may be money. It may be a document. In the case of cryptography it’s usually a key. It’s the encryption keys.

And the encryption key, for some third party to hold it, needs to be stored so that we would have some way to decrypt information should something happen to the original key. It’s a very important part– especially for large organizations that are encrypting a lot of different things– you need some fail-safes in place. But you need to keep the key, obviously, somewhere very, very safe.

You don’t want anybody getting their hands on that key. Because very often everything is built upon that key, whenever we’re doing encryption. And we don’t want people getting into our private information. If you are planning ahead and you are storing these keys, or you have a methodology in place to automatically store these keys, it can save you a lot of time and a lot of grief later.

Sometimes it’s built into the process. Microsoft Windows, for instance, has methods to encrypt entire drives. And you can have those keys automatically stored as part of your Active Directory infrastructure. So depending on what you’re using you may have a few options available to you for key escrow that are already built into your system.

For symmetric encryption, you’re just keeping your key somewhere. Your encryption key and your decryption key are exactly the same. You obviously need to protect those at the end points. But having an extra one stuck in your safe somewhere, locked away, that nobody can get their hands on, would be handy as well.

You also want to think about what you’re doing with asymmetric encryption. The public key, generally, is already distributed in many, many places. There may not necessarily be a need to keep a copy of your public key anywhere because it’s just so accessible.

But the private key– which is the one that does the decrypting, it’s the one the does the digital signatures– that’s the important one that nobody should have their hands on. It make sense to get an additional copy of that decryption key and have it already as part of something that you are escrowing or storing away.

Sometimes the process that we go through with this key escrow is just as important as having that private key itself. You have to think about what circumstances would arise that would require you to go into escrow and get that key? And who has access to the key? Is there more than one key?

Sometimes you can take a private key and split it up into smaller pieces so that you would have to have two or three people all come together in a room to put everything together to be able to have that additional decryption key be able to access that encrypted information. If you have the right process in place, and you have the right ideas behind what you’re doing with key escrow, this can really be a valuable part of maintaining the integrity and security of your data.