Public Keys not showing up in "Choose Recipients"

[David Smith]

On 03/05/13 16:45, BassToGo123 wrote:
> I apologize for my inpatients. I have scoured the internet for a
> discussion board or some other way of finding support for this program,
> and this board is the only one I could find. Not that it matters to
> anyone here, but not resolving this problem in a timely fashion is going
> to cost me.
> 
> If you or anyone here knows of a support forum, I'd love to hear about
> it as I simply cannot locate one and this is the first place that comes
> up when looking for such a place.
> 
> I cannot thank you enough for your reply. This subkey, if a public key
> is imported (the key offered with the intent of it being used to write
> with) without a subkey included, it is simply unable to be written with
> by choice of its owner?

Some reasons why the key may be unusable:

1. It may be expired.  Keys can be (and often are) generated with expiry
dates.  Even if the key has an expiry date in the future, there may be a
problem with the clock setting on the sending device - it could be set
to a date in the future, past the expiry date of the key.  Also, I
believe I am correct in saying that once gpg has noticed that a key has
expired, it marks the key as expired, which is a one-way process.  So,
whilst the clock may be correct now, it could have been wrong in the
past, causing gpg to mark the key as expired, and now the clock is
correctly set, the key is still marked as expired.  To fix this, you
could delete and re-import the key.

2. It may require the use of an algorithm which is not supported - for
example, the key may have been generated for use with the IDEA
algorithm, which isn't supported in many versions of GnuPG.

Outside of this, I'm not sure what to suggest. You've not said which OS
you're using; if you are using one of the Unix variants, I would suggest
running "gpg --list-keys <name_of_recipient>" and then posting the
result to the list.  If you're running a different OS, then I'm not
entirely sure how you get to this information.

I'm also not entirely sure whether you're running GnuPG or not - maybe
the programs you are using are a front-end for gpg, maybe not.  You've
used the terms "GPG Keychain Access" and "PGP Keychain Access", so I
don't know whether you're using PGP, GnuPG, or something else
altogether.  Note that "OpenPGP" refers to the data format of the
encrypted file (and the algorithms required to produce and use it), not
any particular application, so the application(s) you are using may have
no relevance to GnuPG whatsoever.

HTH...