FREQUENTLY ASKED QUESTIONS ABOUT PGP 2.6.3i ******************************************* Last update: 12 June 1996 [The following is a list of Frequently Asked Questions about PGPi (the international PGP versions) with answers. This document is also available in HTML format from http://www.ifi.uio.no/pgp/FAQ.shtml. Comments and corrections may be sent to stale@hypnotech.com.] CONTENTS 1. International vs US version 1.1. Why create an international PGP version? 1.2. What is the latest international version of PGP? 1.3. How does PGP 2.6.3i differ from MIT PGP 2.6.2? 1.4. How is PGP 2.6.3i compatible with other PGP versions? 1.5. What is RSAREF? MPILIB? What is the difference? 2. Legal issues 2.1. What does "international" mean? Who may use it? 2.2. Why isn't it official? Is it illegal to use? 2.3. Can I use PGP 2.6.3i for commercial purposes? 3. Getting it 3.1. Where can I get a copy of PGP 2.6.3i? 3.2. Is there a Windows version of PGP 2.6.3i? 3.3. How can I check the integrity of PGP 2.6.3i? 3.4. Where can I get updated language modules for PGP 2.6.3i? 4. Miscellaneous 4.1. Isn't PGP 2.6.3i the version that was weakened for export by the NSA? 4.2. Are there any bugs in PGP 2.6.3i? 4.3. Who is responsible for PGP 2.6.3i? 4.4. Where can I learn more about PGP? 1.1. WHY CREATE AN INTERNATIONAL PGP VERSION? The official PGP versions from MIT (the latest of which is 2.6.2) were made inside the USA and intended for use in the USA alone. Due to special patent and copyright issues in the US, these versions contain a number of limitations and restrictions that are totally irrelevant for users elsewhere. When PGP has spread to the rest of the world, it is only natural that these limitations are removed. That's why we have the international PGP versions. :-) 1.2. WHAT IS THE LATEST INTERNATIONAL VERSION OF PGP? The latest international version of PGP is 2.6.3i. It was first released on 18 January 1996. PGP 2.6.3i is based on the source code for MIT PGP 2.6.2 and modified for international use. PGP 2.6.3i replaced PGP 2.6.2i. 1.3. HOW DOES PGP 2.6.3i DIFFER FROM MIT PGP 2.6.2? The following are the most important differences: 1. It does not use the RSAREF encryption library 2. It is compatible with all other PGP 2.x versions 3. It corrects a number of bugs present in PGP 2.6.2(i) 4. It compiles "out of the box" for many new platforms 5. It adds some new features without breaking compatibility with earlier versions For a complete list of changes, refer to the PGP263I.DIF file in the source code distribution. 1.4. HOW IS PGP 2.6.3i COMPATIBLE WITH OTHER PGP VERSIONS? PGP 2.6.3i can read and understand messages, keys and signatures created with any 2.x version of PGP. (Note, however, that the keys cannot be larger than 2048 bits. No official PGP version uses larger keys, though.) Because it uses MPILIB rather than RSAREF, PGP 2.6.3i is even capable of understanding the old key signature format in PGP 2.2 and earlier versions (pkcs_compat=0). It cannot write such signatures, though. PGP 2.6.3i can generate messages, keys and signatures that can be read and understood by any PGP 2.x version of PGP. However, if you want your messages to be readable by PGP 2.3a and earlier versions, it is necessary to uncomment the "legal_kludge = off" line in your CONFIG.TXT file. 1.5. WHAT IS RSAREF? MPILIB? WHAT IS THE DIFFERENCE? RSAREF is a software library that implements the RSA cryptography routines. (RSA is one of the encryption routines used in PGP, and the very heart of public key encryption.) RSAREF is freeware, and is released by RSA Data Security Inc., the patent holder of the RSA algorithm in the US. Everyone in the US who wants to make use of RSA in their programs and give it away for free (e.g. PGP), must use RSAREF. All official MIT versions of PGP, starting with version 2.5, have been using RSAREF. MPILIB is simply another implementation of the same RSA routines as found in RSAREF. The MPILIB routines were originally written by Phil Zimmermann, and were used in all PGP versions up to and including version 2.3a. Functionally, MPILIB is identical to RSAREF, but the routines are generally faster than the RSAREF routines (although the speed difference varies between machine platforms). In addition, MPILIB is capable of understanding the old key signature format in PGP 2.2 and earlier versions (pkcs_compat=0). RSAREF, on the other hand, cannot read such signatures. Furthermore, MPILIB is published under the terms of the GPL, whereas RSAREF is not. Please note that PGP 2.6.3i uses MPILIB, _not_ RSAREF. This is the main reason why PGP 2.6.3i should not be used within the US. Phil Zimmermann said this about PGP 2.6.i, the predecessor to 2.6.3i: "The unofficial variant of PGP named PGP 2.6.i by its developers replaces RSAREF routines with other code implementing RSA-related algorithms. I am very familiar with that code, and while I tried to make PGP use RSAREF in a manner that did not suffer a performance penalty, I believe that these other subroutines are at least as efficient, as well as being functionally identical for PGP's purposes. Since the RSA patent does not exist outside the USA, it seems reasonable to not encumber European users with the RSAREF subroutine library and its own additional copyright restrictions..." 2.1. WHAT DOES "INTERNATIONAL" MEAN? WHO MAY USE IT? PGP 2.6.3i was put together to provide an alternative to the American versions of PGP, which are distributed by MIT and contain a number of restrictions that are not relevant for users outside the USA. In general, "international" means "non-US", i.e. it may be used by anyone except those who live in the US. 2.2. WHY ISN'T IT OFFICIAL? IS IT ILLEGAL TO USE? PGP 2.6.3i is perfectly legal to use provided that you: 1. Don't live in a country where encryption is illegal (such as France, Russia, Iran, Iraq or China). 2. Are not physically inside the USA. 3. Make sure that you don't download a copy of PGP that is physically inside the USA. The reason why PGP 2.6.3i is not official, is that is was based on source code that was once illegaly exported from the USA. However, once the program has been exported, anyone may use it freely. 2.3. CAN I USE PGP 2.6.3i FOR COMMERCIAL PURPOSES? Yes, you can, but you need to buy a separate license for the IDEA algorithm used in PGP. (RSA is not patented outside the US, so you don't need a license for this algorithm.) IDEA licenses can be purchased from Ascom Systec AG in Switzerland. (The licensing of the IDEA algorithm was formerly administrated by Ascom Tech, but this responsibility has been transferred to Ascom Systec. Please, do not contact Ascom Tech about this matter!) The fee is charged on a per-user basis as follows: 1.. 50 users 15 US$ per copy 51.. 100 users 10 US$ per copy 101.. 250 users 8 US$ per copy 251.. 500 users 7 US$ per copy 501..1000 users 6 US$ per copy > 1000 users on request The end-user license can be ordered online via WWW: http://www.ascom.ch/Web/systec/security/enduser.htm For more information, contact Licensing Manager Roland Weinhart at: Ascom Systec AG IDEA Licensing Gewerbepark CH-5506 Maegenwil Switzerland Phone : +41 62 889 59 54 Fax : +41 62 889 59 54 Email : idea@ascom.ch WWW : http://www.ascom.ch/Web/systec/ 2.4. CAN I USE PGP CODE IN MY OWN PROGRAMS, AND IF SO, HOW? PGP is distributed under the General Public License (GPL), so you are free to modify the program for your own use. But don't use it for commercial purposes, and if you intend to release any code that is derived from the PGP sources, don't call it by the name "PGP", as it is a registered trademark. For more information, see volume 2 of the PGP User's Guide. Unfortunately, there is no such thing as a PGP DLL. Thus, integrating PGP into your own programs is a little difficult. There are at least three ways to do this: 1. Use temporary files and call an external PGP binary with the correct command line parameters (slow) 2. Get a copy of PGP Tools and see if you can make any sense of it 3. Modify the PGP source code distribution and link it into your own programs (difficult) 3.1. WHERE CAN I GET A COPY OF PGP 2.6.3i? PGP 2.6.3i is available both as source code and as precompiled binaries for some of the most popular platforms, such as MS-DOS, OS/2, Atari, Amiga and Macintosh. To obtain a copy of PGP 2.6.3i, try: WWW: http://www.ifi.uio.no/pgp/ FTP: ftp.ifi.uio.no/pub/pgp/ idea.sec.dsi.unimi.it/pub/security/crypt/PGP/ ftp.encomix.es/pub/pgp/ ftp.ox.ac.uk/pub/crypto/pgp/ E-mail: Send a message to pgp@hypnotech.com with your request in the Subject field. Subject What you will get ------- ----------------- GET pgp263i.zip MS-DOS executable (base64) GET pgp263ix.zip 32-bit MS-DOS executable (base64) GET pgp263i-os2.zip OS/2 executable (base64) GET pgp263i-win32.zip Windows 95/NT text-mode executable (base64) GET Amiga-PGP Amiga executable (uuencoded) GET Atari-PGP Atari executable (base64) GET MacPGP Macintosh executable (HexBin) GET pgp263is.zip Source code, MS-DOS line feeds (base64) GET pgp263is.tar.gz Source code, UNIX line feeds (uuencoded) GET MacPGP source Additional source code for Macintosh (HexBin) Note: The uuencoded files are not split in any way, but sent in one portion. Because some of the files are very big (more than 800 kbytes), this may cause problems if your mail system cannot handle messages of this size. If you don't get a reply, this is probably the reason. 3.2. IS THERE A WINDOWS VERSION OF PGP 2.6.3i? No. There is no "true" Windows 3.1/NT/95 version of PGP, but there exists a number of front-end shells that wrap around the DOS versions. Precompiled binaries exist for MS-DOS (16-bit & 32-bit), OS/2, Amiga, Atari and Macintosh. There is also a Win32 (Windows 95/NT) compilation, but it's only a text-mode application without any fancy GUI. 3.3. HOW CAN I CHECK THE INTEGRITY OF PGP 2.6.3i? All the PGP 2.6.3i distribution archives contain a signature file so that you can verify that the files have not been tampered with. In order to verify the signature, you need the signatory's public key: Stale Schumacher (0xCCEF447D): source code, MS-DOS, Mac and OS/2 versions Peter Simons (0x34D74DC1) : Amiga version Guy Geens (0xAB2A3F25) : Atari version All keys are available from a public keyserver. For details, send email to pgp-public-keys@keys.pgp.net with HELP as the Subject. 3.4. WHERE CAN I GET UPDATED LANGUAGE MODULES FOR PGP 2.6.3i? An updated collection of translation files for both PGP 2.6.3 and 2.6.3i can be found at the PGPi Language Page, available via WWW from: http://www.ifi.uio.no/pgp/modules.shtml Alternatively, you can get them via anonymous FTP from: ftp.ifi.uio.no/pub/pgp/lang/ ftp.encomix.es/pub/pgp/lang/ ftp.ox.ac.uk/pub/crypto/pgp/language/ 4.1. ISN'T PGP 2.6.3i THE VERSION THAT WAS WEAKENED FOR EXPORT BY THE NSA? No. PGP 2.6.3i is just as secure as any other version of PGP. Neither Phil Zimmermann, MIT, NSA, myself nor anybody else have put any backdoor into PGP 2.6.3i, limited the effecive key size or otherwise done anything to compromise the security of the program. If you don't believe it, download the source code and see for yourself. The PGP source is free for anyone to scrutinize, and has been so for many years now. Still, nobody has been able to find any backdoors. Strange, isn't it? 4.2. ARE THERE ANY BUGS IN PGP 2.6.3i? No program is 100% error free. Yet PGP 2.6.3i is probably the most bug- free PGP version available today. To see a list of known bugs and how to fix them, please refer to the PGPi Bugs Page, available via WWW from: http://www.ifi.uio.no/pgp/bugs.shtml To report new bugs, send email to pgp-bugs@ifi.uio.no. 4.3. WHO IS RESPONSIBLE FOR PGP 2.6.3i? PGP 2.6.3i was put together and published by Stale Schumacher in Norway. However, this work would not have been possible without the help of many individuals around the world. The international PGP versions are now maintained and supported by an international development team, who coordinate their work through an Internet mailing list. If you would like to join this list, please contact stale@hypnotech.com. All questions regarding PGP 2.6.3i should be addressed to pgp-bugs@ifi.uio.no. Please note that Phil Zimmermann, MIT and the University of Oslo have nothing to do with PGP 2.6.3i. Comments, bug reports and suggestions for future releases are welcome. 4.4. WHERE CAN I LEARN MORE ABOUT PGP? The README.1ST file in the PGP 2.6.3i distribution covers most of the details that are special to the international PGP versions. If you have access to WWW, the PGPi Home Page is an excellent starting point for further PGP exploration: http://www.ifi.uio.no/pgp/ For information on PGP and encryption in general, check out the following resources: Other FAQs: PGP Frequently Asked Questions from alt.security.pgp http://www.prairienet.org/~jalicqui/pgpfaq.txt ftp://ftp.prairienet.org/pub/providers/pgp/pgpfaq.txt Where to Get the Latest PGP Program FAQ ftp://ftp.uu.net/usenet/news.answers/pgp-faq/where-is-PGP.Z WWW: Fran Litterio's PGP Page (from the Virtual Library) http://world.std.com/~franl/pgp/pgp.html The Official Bug List for MIT PGP 2.6.2 http://www.mit.edu:8001/people/warlord/pgp-faq.html FTP: ftp://ftp.ifi.uio.no/pub/pgp/ ftp://ftp.dsi.unimi.it/pub/security/crypt/PGP/ ftp://ftp.ox.ac.uk/pub/crypto/pgp/ Newsgroups: alt.anonymous discussion of anonymity and anon remailers alt.anonymous.messages for anonymous encrypted message transfer alt.privacy.clipper Clipper, Capstone, Skipjack, Key Escrow alt.security general security discussions alt.security.pgp discussion of PGP alt.security.ripem discussion of RIPEM alt.security.keydist key distribution via Usenet alt.society.civil-liberty general civil liberties, including privacy comp.compression discussion of compression algorithms comp.org.eff.news news reports from EFF comp.org.eff.talk discussion of EFF related issues comp.patents discussion of S/W patents, including RSA comp.risks some mention of crypto and wiretapping comp.society.privacy general privacy issues comp.security.announce announcements of security holes misc.legal.computing software patents, copyrights, computer laws sci.crypt methods of data encryption/decryption sci.math general math discussion talk.politics.crypto general talk on crypto politics Books: The Official PGP User's Guide by Philip R. Zimmermann MIT Press 1995 ISBN 0-262-74017-6 216 pp. $14.95 PGP: Pretty Good Privacy by Simson Garfinkel O'Reilly & Associates 1994 ISBN 1-56592-098-8 430 pp. $24.95 Protect Your Privacy: The PGP User's Guide by William Stallings Prentice Hall PTR 1995 ISBN 0-13-185596-4 302 pp. $19.95 Applied Cryptography: Protocols, Algorithms, and Source Code in C 2nd Edition, by Bruce Schneier Wiley Publishing 1996 ISBN 0-471-11709-9 E-Mail Security: How to Keep Your Electronic Mail Private by Bruce Schneier Wiley Publishing ISBN 0-471-05318-X