National Aeronautics and Space Administration

• Introduction
• Obtaining and installing GPG
• Decrypting your RXTE realtime data

Introduction

PGP, or Pretty Good (TM) Privacy, is a high-security cryptographic software application that allows people to exchange information with both privacy and authentication. It was written by Philip Zimmermann, and uses an algoritm (IDEA) that has now been patented. GPG is GNU Privacy Guard, a PGP replacement which is free and does not use the patented IDEA algorithm. Each program can unencrypt files encrypted by the other, within certain limitations outlined below.

The RXTE mission makes proprietary data available for download as encrypted tar files. The encryption key is sent to the PI, usually when the observation is scheduled. When electronic distribution of RXTE data began, PGP was used for data encryption. In February 2006, RXTE switched to using GPG for all realtime and full-processing data distribution, due to the greater availability of GPG and its broader support of modern computer platforms. The impact on RXTE users is as follows:

Software for Unencrypting RXTE Proprietary Data

If you have:	You should:
GPG 1.06 or higher	do nothing - you will be able to unencrypt both newer and older RXTE data
GPG < 1.06	update your version of GPG - your version is too old to unencrypt RXTE data
PGP 6.0 or higher	do nothing - you will be able to unencrypt both newer and older RXTE data
PGP < 6.0	get GPG - your version of PGP is too old to unencrypt the newer RXTE data (see text, above)
Neither PGP or GPG	get GPG

The recipe below tells more about how to obtain and apply GPG to RXTE data. Note that using the recipe below does not absolve you from the responsibility of reading and understanding the documentation provided by GPG at their Web site. Also, bear in mind that for various legal and practical reasons the RXTE mission cannot provide the same complete support for GPG as for our own in-house software like FTOOLS, Xanadu etc.

1. Connect to the GPG Homepage.

2. We suggest new users start with the "HOWTOs", linked on the left side of the GPG homepage, under "Documentation". These are 'How To' guides available in various formats and languages (eg., en=english, it=italian, etc.)
3. Also check the "Supported Systems" under the "Download" section (just above "Documentation") to see the latest list of supported systems; this section also contains special notes for some platforms (eg., Mac OS X).

1. Look in your schedule notification for the access key, which will be a many-digit number.
2. Download the dataset(s) you wish to analyze:
   • Via the Web: Go to the appropriate Web site -
     RXTE PGPData area (for fully processed datasets)

     RXTE SOF (for realtime and pseudo-production datasets)

     Find and save your data to your computer. (In many browsers, this is done by holding the right mouse button while pointing to the dataset, and selecting "save link as".)
   • Via Anonymous_FTP: connect to one of the two sites below, and follow instructions:

     For Fully Processed datasets (RXTE PGPData area):

     ftp heasarc.gsfc.nasa.gov
     (give "anonymous" for userid and e-mail address as password)
     cd xte/data/archive/PGPData
     get obsid.tar.pgp
     quit

     For Realtime or Pseudo-production datasets (XTE SOF site):

     ftp xgo2.nascom.nasa.gov
     (give "anonymous" for userid and e-mail address as password)
     cd pub/FITS/
     get obsid.tar.pgp
     quit

3. To decrypt your data, type:
   gpg obsid.tar.pgp

   and when prompted for the pass phrase, use the access key from (1).

4. Untar the data and proceed with analysis; if you are analyzing realtime data from the RXTE SOF, be sure to refer to the RXTE recipe Working with Realtime Data.

This page is maintained by the RXTE GOF and was last modified on Wednesday, 24-Aug-2022 11:10:30 EDT.