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7

You cannot reconstruct an OpenPGP key based on it's fingerprint. The fingerprint is a hash value of the public key, so calculating the fingerprint of a key is a one-way operation. But: if somebody only distributes his key's fingerprint, he will almost certainly have distributed his public key on the key server network, from where you can pull it. Given you ...


1

Could you not generate the encryption key based on a pass phrase given by the user that is encrypting the data? Then that pass phrase would have to be supplied again in order to decrypt the encrypted data. This would of course require the pass phrase to be known and entered by a user so nothing would just magically happen.


1

No, although the reason I see is independent of most of your post. CBC mode is malleable; you should use a MAC too.


0

I wouldn't have thought this was a good idea. The TPM can only provide "trust" for keys that were created within the TPM. Otherwise, who knows what happened to the keys before they were added to the TPM? If the private key ever exists outside the TPM, all bets are off.


1

Not with a PSK. But what you ask for is something OpenVPN provides with it's TLS mode. That will periodically negotiate new keys for you automatically. If you do want the networking to be peer-to-peer, like in PSK mode, you can use configs similar to those in the loopback-server and loopback-client configs in the OpenVPN config files. Something like this ...


20

There is a standard for that, and, more generally, for all communications with a PKI. It is called CMP. Revocation requests are specified in section 5.3.9. Now, finding a PKI that actually implements CMP... this may be challenging.


0

First of all, please take @Joseph Kern's answer seriously! Think how hard it is to play an audio tape or access the data on a floppy disk nowadays—both storage formats were prevalent and widespread in the 1990's, only two decades ago. You mentioned USB sticks: the standard USB-plug will be gone within a decade, replaced by the new USB-C plug and that will ...


3

Backups and Archives Oh My! Based on my unscientific Googling First issues first, let's turn this into a scientific exercise (library science!), the decisions you make today will affect people that you haven't (or might never) meet. You've mentioned two of your three options for key management; analogue and digital. Have you considered your third ...


1

As @whoami mentioned, it does just move the issue to another place. As you mentioned it allows you to move it out of code (if you've hardcoded it), password protect it (if it was originally just a PEM or whatever on disk), and ACL it to the requisite permissions. The problem is that you do need to know the key to unlock it, and that of course requires ...


3

I'm also interested in the practicalities of paper backup, in particular tools that allow adding error-detection and error-correction capabilities similar to what RAR does for archives (i.e. dial-your-desired-security), and perhaps encodings that are more efficient and/or robust in the face of OCR than, say, base64. Have you considered combining paper ...


3

@curious_cat has a great answer. I'm going to add a few other areas, though. First, what's your budget for this? You need the budget in three areas: Capital and operational expenditure for inital start-up buying HD-Rosetta capable addressable microscopes, equipment to etch stone or clay tablets, OCR scanners that can handle stone or clay tablets, etc. ...


14

What about something like Verbatim's Archival Grade Gold DVD-R>? It gives 4 GB storage. They claim a life of "up to 100 years" but I find no independent verification. Frankly I'm skeptical. But maybe you can boost your chances by just burning the same data on to multiple disks and hope any failures are uncorrelated? I'd buy disks from different lots or ...


0

Merging the user ID packets would be indeed possible -- but you'd have to create a new self-signatures afterwards for the user ID. You could use gpg-slit to cut apart the individual OpenPGP packets, and reconcatenate them using cat while putting the user ID packet at the right place (be aware: this requires deeper understanding of RFC 4880, OpenPGP). But ...


1

There is a variation of TLS that uses a Pre-Shared Key instead of certificates, called TLS-PSK. This basically works the same way as usual TLS except the session key is generated in a different way. You should take a look at this.


1

A GPG_AGENT is a program that when asked, (de|en)crypts the data for the caller (in this case using gpg). The 'files' you see are most probably sockets for communicating with the agent. Once the program is closed (or locked), it can't be used, those files don't contain any private information, agents are (generally) pretty-well designed, and won't even ...


0

Implementing application level encryption on Linux servers is a bit tricky as the application needs to be able to get the encryption key from somewhere and you don't want this to be in clear text anywhere. From a regulatory perspective, you'll likely want there to be dual control and split knowledge for encryption keys. You could have some level of logical ...


0

The Version header is purely informative; my guess is that it's included to make compatibility bugs easier to discover (e.g. if a client is unable to decrypt 10 messages, and all 10 were made by the same version). Source: http://superuser.com/a/823907


3

As far as I do understand, you want to convert an authentication subkey to an SSH key, and authenticate using this. If I generate a PGP subkey that only has the authentication capablity and use this to generate an SSH keypair to authenticate Git for example, does this pose a security threat? Whether this is reasonable or not depends on what you're ...


5

The problem is probably not so much algorithmic security. The problem is that if there is a security problem with one of the applications that you also have a security problem the other application. Furthermore, it may be that some kind of attacks on the protocol may be made possible because you share keys. In other words, this is not a good idea with ...



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