Hi there -

I have a couple of old files which were encrypted using some sort of
encryption program (for Windows).  It was probably freeware or
shareware, and it was about 4 years ago.  I suspect I'd be able to
recreate my passphrase given two or three attempts, but I can't
remember what the software was that I used to encrypt them, and so
can't unencrypt.  The files end in the rather dramatic extension
".$#!" (e.g. the filename of one is "supersecretstuff.$#!").  Can you
find out for me what encryption software created "$#!" files and
whether I could download or buy it from someone?

Hello slithytove

According to the excellent filext.com website the .$#! extension has
been/is used by two companies and/or programs.

The first possible answer, which I think we can discount in your case,
is that the extension was used by AOL in version 5 of its software as
a "virus checking" file.

The other possibility, which I believe is the answer you are looking
for, is that it was used by Nick Payne in his Cryptext program.

Confirmation of these two possibilities can be seen here:
http://filext.com/detaillist.php?extdetail=%24%23%21

More details on Cryptext can be found on its homepage:
"Cryptext is a public domain Windows shell extension that performs
strong file encryption and runs on Windows 95 or later and NT4 or
later. It is available in English, French, German, Spanish,
Portuguese, Italian, Hungarian, Danish, and Finnish language versions.
You just right-click on any file system object to encrypt or decrypt
it. It uses a combination of SHA-1 and RC4 to encrypt files using a
160-bit key, and generates a salt value for each file to ensure that
no two files are encrypted with the same keystream."
http://www.pcug.org.au/~njpayne/

Cryptext, which appears to be free, can be downloaded from:
http://www.pcug.org.au/~njpayne/download.html

I hope this has fully answered your queries.  Should you have any
further questions on this subject please ask for clarification and I
will do my best to help.

BEAUTIFULLY done!!  And so quickly -- plus now I know about
filext.com!  Palitoy, you rock.  Thank you so much for your help.  I
downloaded Cryptext, installed, decrypted my old files, and am very
very happy.  Thank you!!

Thank-you for the 5-star rating, generous tip and praise.  They are
all greatly appreciated.  I'm glad I could help!