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New Mailing List: Terrorism
by John Gilmore 17 Dec '03

17 Dec '03

Sounds like some "civil rights oriented" EMS, fire, law enforcement, intelligence community, etc people should join, and let the rest of us know what they are doing... John From: churton.budd(a)mediccom.org (Churton Budd) Date: Sat, 11 Oct 1997 10:55:40 GMT TERRORISM --------- TERRORISM is intended for discussion about terrorism response and prevention, including intelligence gathering and emergency responses. Topics include weapons of mass destruction, suspicious activities, educational and funding opportunities, politics, and response ideas. TERRORISM is an open forum to EMS, fire, law enforcement, intelligence community, disaster preparedness & response, and military personnel with an interest in preventing and responding to terrorist incidents. Announcements about new educational opportunities and grants are welcome, as are new products, services, or technologies directly related to terrorism response. Listname: terrorism Post to: terrorism(a)mediccom.org subscription command: subscribe terrorism sent to: listserv(a)mediccom.org

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why Phil Zimmermann should be speaking out against pgp5.5 and CMR
by Adam Back 17 Dec '03

17 Dec '03

(Readers may notice PRZ's email address on the Cc line, this is an open letter addressed to him). In the debate on the controversial pgp5.5 commerical message recover (CMR) system, I noticed someone made the comment that they couldn't see what the big deal is with enforced multiple crypto recipients who aren't also message recipients, as pgp2.x has had non-enforced multiple crypto recipients for ages. I will put the case for why this practice should be avoided for security reasons. I would like to also put the case of why the enforced multiple crypto recipient construct should be avoided in building messaging systems where the designers would like to avoid building GAK compliant systems. The security reasoning is simple: there are is an extra door into the encrypted data: via the CMR key. Introducing an extra door reduces security, because there are now two keys which could be compromised to gain access to the data. That was simple. Possibly not that major a problem, perhaps both keys are so well secured that the additional leakage is academic. In that case, fair enough. Now the GAK compliant case: Firstly it is important to understand the subtle but very significant difference between enforced crypto recipients who aren't message recipients and normal pgp2.x style multiple crypto recipients. This difference is as much to do with the way that mail clients and plugins have used the pgp2.x multiple crypto recipients in fielded systems as with the actual messaging packet differences. A message recipient is someone who's email address is listed in a To: Cc: or Bcc: field in your mail client. A crypto recipient is someone who will be able to decrypt the message. Pgp is a hybrid crypto system, a message consists of the email encrypted with a randomly generated symmetric key, the session key. The session key is in turn encrypted to the public key of the recipient, these are called Public Key Encrypted (PKE) packets. To implement multiple crypto recipients pgp simply tacks on as many PKE packets as there are crypto recipients; each PKE packet being the session key encrypted to the public key of one of the crypto recipients. Now in most fielded PGP email plugins, and clients which take notice of Cc: and Bcc: fields, the number of crypto recipients ties directly with the number of message recipients. This makes it difficult therefore for the existing systems to automate encryption to a third party without software modifications. If a company which is hoping to become a market leader (a hint PGP) were to retain this functionality, GAKkers would find it difficult to use this software to effectively impose GAK. Sure you can Cc: your message to the NSA key. This would be voluntary GAK. Carl Ellison and a number of others suggested this whimsically years back. As in "What's all the fuss about voluntary key escrow, I'll implement voluntary key escrow for you right now, get DIRNSA to generate a key, and I'll sign it, and put it on the keyservers -- end of problem". Carl Ellison had a very good point. The government doesn't want voluntary key escrow, they want as some suspected all along mandatory key escrow, they want GAK (the GAK term is coincidentally another Carl Ellison meme). The reason this is voluntary GAK is that the user in most mail systems would have to go to some concious effort to do this, and may forget some of the time. (It's difficult to make "forgetting" a 5 year jailable offense). Now I'm well aware that some email clients, and MTAs will no doubt allow you to forward copies of all your email transparently to another party. (Please don't flood us with replies describing such functionality). But this is not really the point; it doesn't matter if you can forward copies of your encrypted email "thoughtpolice(a)nsa.gov" -- they can't decrypt it with out the recipients key. Now we come to the danger of PGP Inc's CMR mechanism. CMR breaks this traditional premise that the crypto recipients correspond one-to-one with the message recipients. What it allows is instructions to be given in a public key that tell the software to encrypt messages intended for the owner of this key to two message recipients. This means that for example: If Phil Zimmermann is using his own companies pgp5.0 mail client (and I presume he is), that if the US Government were to pass a law requiring everyone to generate new CMR keys that he would be able to comply without changing his software. This is why I would argue that even pgp5.0 is GAK compliant, it knows how to understand CMR public keys. (I am not actually sure if the pgp5.0 mail client can generate CMR public keys, but the pgp5.5 one can for sure, I'd welcome clarification on this point). The new mandatory GAK law would mean that if he didn't generate a CMR key he would go to jail. So he complies. The terms of the law dictate that the CMR recipeint in individual's mail clients must be "thoughtpolice(a)nsa.gov". Now the next time one of PRZ's favourite resistance groups that he likes to tell us stories about send him an email thanking him for the useful piece of software he provided them with, the USG can listen in because the pgp5.0 software which the resistance fighters have presumably also upgraded to will understand PRZ's CMR key. The USG will if it suits their purposes sell this information to the government in the originating country, and they will have the death squads go kill the resistance fighters if they can determine their identities from the leaked message. This kind of makes a mockery of what PRZ and the PGP brand stands for. Now the pgp 5.5 defenders at PGP Inc will jump up at this point and tell us that this is not so because pgp 5.0 has ability to strip out the second enforced recipient. Well it does. However, PGP Inc has come up with another related clever innovation: their SMTP policy enforcer. This ensures that when resistance fighters attempt to send PRZ email inside the PGP Inc offices (where they will be presumably field testing their GAKware software suite), that if they do take off the CMR recipient, that their mail will bounce. So not being technical crypto gurus, they will try not taking it off next time and the NSA will read the mail again, resulting in the resitance fighters death. Or perhaps alternatively if they really did want to send him email for an important reason, like perhaps to warn him that the corrupt government they were fighting against was going to introduce a law of mandating the use of pgp5.5 by all ISPs and individuals, they would have no way to reach him. This would suit PRZ quite well, because he probably wouldn't want to hear that. Actually it is possibly not fair to pick on PRZ, as I consider it somewhat likely than PRZ is dragging his feet internally to PGP, but is powerless to stop the corporate mindset now at the helm. And if so I apologise for making points at his expense. But also it is important that if PRZ is against this move, that he speak up. That act would have major significance in altering PGP Incs mind. It might also result in a parting of the ways, but I understand from attenders at a physical cypherpunks meeting in the US that PRZ when quizzed about PGP Inc corporate mentality meaning the company would eventually sell out to GAK, relayed that he would quit rather than have be associated with this. Adam -- Now officially an EAR violation... Have *you* exported RSA today? --> http://www.dcs.ex.ac.uk/~aba/rsa/ print pack"C*",split/\D+/,`echo "16iII*o\U@{$/=$z;[(pop,pop,unpack"H*",<> )]}\EsMsKsN0[lN*1lK[d2%Sa2/d0<X+d*lMLa^*lN%0]dsXx++lMlN/dsM0<J]dsJxp"|dc`

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Re: Encryption Program
by Randall Farmer 17 Dec '03

17 Dec '03

Although I don't know the PRNG in Visual Basic (the one 3dmx uses) well enough to do much real analysis, the description of an attempt to correct a problem in it shows a weakness in the "enhanced" version...here's a slightly abridged/clarified copy of the message I sent the author about it. ------------------------------------------------------------------------------- <headers snipped> ... > While it is true that PRNG's are not very good, Well, there isn't any big problem with PRNGs as a class -- RC4 is based on a PRNG, and it's okay to use as long as you know its limitations (i.e., just so you don't try using the same key twice or anything similarly silly). ... > I believe I found a way around that problem...I used a syst[e]m of cubic > arrays. The program first creates sixteen cubic arrays, and fills them one > space at a time with random characters. When the stream of characters to be > XORed with the plaintext is generated, it picks a random cube and a random > location with[in] that cube. I can't do much real analysis since I don't know how Visual Basic's PRNG works, but with a truly secure PRNG like one you would see in a good stream cipher, you can't predict x bits of the PRNG's output with more than 1/2^x probability of bring right without doing exhaustive search of the keyspace. However, your arrays almost surely won't be filled with the *exact* same quantity of each character, so, even if the bytes in your PRNG's output are selected randomly from the arrays, some bytes are more likely to be a byte in your "enhanced" PRNG's output than others. Therefore, given a bunch of the stream, one can guess the next 8 bits of the PRNG's output with more than 1/256 probability of being right, meaning your PRNG doesn't fit the bill. To sum it up, no matter what Visual Basic's PRNG does, that method *can't* be 100% secure. ... --------------------------------------------------------------------------- Randall Farmer rfarmer(a)hiwaay.net http://hiwaay.net/~rfarmer

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Re: proposal: commercial data recovery
by goddesshera＠juno.com 17 Dec '03

17 Dec '03

On Tue, Oct 14, 1997 at 10:37:21AM +0100, Adam Back wrote: > > If we take the design goal of designing a commercial data recovery > system which is not GAK compliant, we can most succinctly state this > design goal as the task of ensuring that: I take a certain sad pleasure in reminding people that among my first posts on this list I warned that cypherpunks had better design a commercial key recovery system, or one they didn't like would be forced down their throats. Attila now spouts my line exactly, Adam is busy designing (though he still can't bring himself to use the term 'key recovery', being meme-dominated as he is), and Tim nods approvingly. Good luck, gentlemen -- you should have been doing this a year ago. -- Kent Crispin "No reason to get excited", kent(a)songbird.com the thief he kindly spoke... PGP fingerprint: B1 8B 72 ED 55 21 5E 44 61 F4 58 0F 72 10 65 55 http://songbird.com/kent/pgp_key.html This message was automatically remailed. The sender is unknown, unlogged, and nonreplyable. Send complaints and blocking requests to <goddesshera(a)juno.com>.

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Re: the case for separate comms keys
by pgut001＠cs.auckland.ac.nz 17 Dec '03

17 Dec '03

Death rays from Mars made Adam Back <aba(a)dcs.ex.ac.uk> write: >You can also acheive the same flexibility with an extra indirection with >symmetric storage keys (optionally held in escrow). In fact I think this is >what later versions of Peter Gutmann's SFS do. The reason he uses for this is >that it allows you to change your passphrase without re-encrypting the whole >disk, because the _actual_ disk encryption key is encrypted itself with the >hash of your passphrase, rather than using the hash of the passphrase directly >as the key. There are also a few other reasons for doing this, and I've extended the idea used in SFS for use with my cryptlib encryption toolkit. Instead of encrypting just the key, you also encrypt the algorithm details, ie: E ( algorithm, algorithmInfo, key ) passphrase E ( data ) algorithm, algorithmInfo, key This makes the job of an attacker somewhat harder because even if they have some means of performing a reasonable attack on the second encryption step, they won't know exactly what it is, so even if it only has a 40-bit key they might need to search half a dozen algorithms before finding the right one. This makes it a lot harder to just brute-force everything going past in the hope of finding something useful. This is especially entertaining for algorithms like RC5 and Safer, where you can produce dozens of variations by playing with algorithm parameters, in effect adding extra bits to the key length. As Adam mentions, you can also escrow[0] the second key (which SFS does using a threshold scheme with the parameters controlled by the user). In this way the user can change their password without destroying the ability of the escrow to access the data. Finally, using the session-key mechanism means you never encrypt two lots of data using the same key, and means you can encrypt a single message for multiple recipients just like the public-key equivalent. Peter. [0] This is "escrow" used in the true sense, not the GAK euphemism. It's completely under the control of the user, it's optional, and it's intended for recovery of stored data when you forget the passphrase.

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Re: CVS: cvs.openbsd.org: ports
by uk1o＠rz.uni-karlsruhe.de 17 Dec '03

17 Dec '03

Hello! [older mail] According to Warner Losh: > In message <199709160731.JAA11130(a)waldorf.appli.se> Niklas Hallqvist writes: > : To people with commit access: committing to ports won't work, it's a > : sup mirror where files will get overwritten. Instead discuss changes > : on ports@ and when good, mail to imp@ with explanations for > : consideration of including into FreeBSD. > This particular patch was committed to the FreeBSD tree last night. > I do think that there will come a time when OpenBSD needs to have its > own ports tree. 95% of this tree could be a mirror of the FreeBSD, > but there are some interesting issues that need to be resolved that > haven't been (like the libcrypt issues). How about suggesting a make variable HAS_LIBCRYPT to the FreeBSD people? We could set it in <bsd.own.mk> or something like this (to a value meaning "we don't have it and we don't need it either), and FreeBSD could do similar. Another way were patching the third party program's Makefile accordingly. We should introduce a patches-${OPSYS} directory having precedence before the patches directory of a port. Thus we could maintain our special patches for ports which need them while continuing to use the FreeBSD ports where they work out of the box. I see now that this is already implemented in <bsd.port.mk>, so we could just USE that. > Warner Regards, Felix.

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Re: CVS: cvs.openbsd.org: ports
by Warner Losh 17 Dec '03

17 Dec '03

In message <E0xLTBc-0001Bo-00(a)rover.village.org> uk1o(a)rz.uni-karlsruhe.de writes: : How about suggesting a make variable HAS_LIBCRYPT to the FreeBSD people? : We could set it in <bsd.own.mk> or something like this (to a value : meaning "we don't have it and we don't need it either), and FreeBSD could : do similar. The problem isn't in the BSD make files, but rather in the makefiles of the ports. True, many FreeBSD ports' patches add -lcrypt blindly to the makefile, but that could change. : Another way were patching the third party program's Makefile accordingly. : We should introduce a patches-${OPSYS} directory having precedence before : the patches directory of a port. Thus we could maintain our special patches : for ports which need them while continuing to use the FreeBSD ports where : they work out of the box. I see now that this is already implemented in : <bsd.port.mk>, so we could just USE that. There already is the patches-${OPSYS} that can be used for this purpose. Warner

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I have seen the future.....
by tech21＠tectel.com 17 Dec '03

17 Dec '03

I HAVE SEEN THE FUTURE And it will change your world soon... I receive a lot of telephone calls. All of them interesting-some of them fascinating. Seldom though, do I receive a call that I would truly refer to as "compelling." That is, of course, until my phone rang about 3 weeks ago. I still can't believe it. Odd call. Gentleman wanted some information-specific information. Of course I had a few questions that I needed answered first. "What's the product?" "Can't tell you," came a rather hollow reply. "Can't tell me? Why not?" I pressed, becoming increasingly more curious-and irritated-by the moment. Seeming to change the subject he said, "We want you to come take a look, and give us your opinion." "Come where? And give you my opinion on what?" "We'll send you a plane ticket." Three days later, I found myself staring out the window of that early morning Delta flight as we made our final approach, wondering what in the world I have got myself into. Met with the founders and the young man who had invented the technology. I guess it was about 55 minutes into the presentation that I understood what these guys were up to, and the profound effect this was going to have upon the world-our world. While I sat there riveted on the CEO's every word, transfixed by the passion emanating from his steel blue eyes, I felt like some character in a spy novel, conspiring on a plot to overthrow the government. One day, I'll tell you the whole story. What you ask could have such a profound effect upon our world? THE TOTAL DESTRUCTION OF THE TELE-COMMUNICATION INDUSTRY AS IT CURRENTLY EXISTS!! I've recently been invited to the high technology company discussed above. It is a new publicly traded company. It will be the Microsoft of the telephone industry. It is extremely well funded and has patented high technology. The proprietary technology is the most significant advance in over 100 years of tele-communications. Protected by 2 patents covering 48 applications, we have a private network infrastructure at a pre-opening investment of approximately 23 million dollars. We are not re-sellers of Long Distance time; rather a direct competitor to AT&T and others. To illustrate the potential of this proprietary technology: the internal cost of AT&T to complete a call is calculated at approximately 3 cents per minute; MCI and Sprint the second and third largest competitor based on cost of approximately 4 cents per minute. Our private network "compression technology" can accomplish the same call for as little as 2/ 100th of a cent per minute. For example, AT&T and MCI just announced they were going to cut their basic rates by 5% during the daytime and 15% during the nighttime. On a 15 minute coast to coast call AT&T's new price will be $4.65 during the day for their average customer, our regular price to every customer every day (24 hours per day, 7 days per week) is $1.18. We can afford to beat AT&T pricing because of our technology. But you ask, do I have to use any special equipment. Absolutely not. Just pick up the phone and call the party you want to reach. Pricing is only the tip of the iceberg with our new technology. Our multimedia products are going to make your life so much easier. Star Trek is here, right now and our smart communications platform will bring it to you. AT&T, MCI, and Sprint, look out there is a new major player in town. We will only work with a limited number of individuals to launch this company. If you think you have what it takes or have proven that you do, do not wait a moment longer. This is a ground floor business opportunity, with a compensation package potentially 300% more lucrative than our nearest competitors. Would you agree I have something here that spells opportunity? If yes, we need to talk further, immediately. Call for information and cassette 1-800-741-6240 or e-mail us at technology(a)tectel.com Please indicate your name, address, and telephone number in the body of your response. ************************************************************ Removal Instructions... It is in no way my intention to send anything to anyone who is not interested in the information; If you would like to receive future updates, simply reply to this message with "subscribe" in the subject line to subscribe(a)tectel.com and indicate your name, address, and telephone number in the body of your response. Please complete all information. If we do not hear from you, you will be automatically removed from future updates and will not be contacted again.

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Document on Customizing OpenBSD after install
by Marshall Midden 17 Dec '03

17 Dec '03

Is there a checklist someplace on what to do after the install of OpenBSD 2.2? I'm thinking like: 1) Go into /etc a) Verify disks and network interfaces configured correctly. Files: fstab, hosts, myname, hostname.le0, mygate, resolv.conf, defaultdomain. You might wish to turn off multicast routing in /etc/netstart. b) Edit motd to make lawyers comfortable and delete "Welcome". c) Fix passwd via "vipw" to change passwords, set up users, etc. Make sure password on "root". Default is no password from console, and disabled from network. Make sure to edit "group" for any user groups, and to put people into the wheel group if they need root access. d) Any local configuration change in: rc.conf, rc.local e) printcap, hosts.lpd Get printers set up f) Tighten security: fbtab Set security for X inetd.conf Turn off extra stuff, add that which is really needed. rc.securelevel Turn on Network Time Protocol. g) kerberosIV Get kerberos configured. Remember to get a srvtab. h) aliases Local mail delivery (set postmaster, etc). Run newaliases after changes. i) bootptab If this is a bootp server. j) ccd.conf If using concatenated disks (striped, etc). k) exports If this is an NFS server. m) NIS (old yellow pages), hosts.equiv, defaultdomain, etc. n) ifaliases for www, etc. o) daily, weekly, monthly. p) "amd" directory if using this package. q) rbootd if needed for remote booting (ethernet MAC address to IP translation). r) Any other files and directories in /etc. 2) crontab -l. Do you need anything else? 3) After the first nights security run, change ownerships and permissions on things. Best bet is to have permissions as in the security list.

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Technical Description of PGP 5.5
by Bill Stewart 17 Dec '03

17 Dec '03

Jon Callas presented a technical description of PGP5.5 at this month's Bay Area Cypherpunks meeting, as well as flak catching on the politics discussion; Phil Zimmermann and other PGP folks also helped. This posting is an attempt to summarize the technical parts and leave the politics for other messages. Perhaps there's been some technical discussion on OpenPGP, but feel free to forward this there if not. 1) PGP 5.5 API Toolkit - It's the core of the PGP5.5 GUI and SMTP tools. It'll be out Real Soon Now. It's a major change from the PGP 5.0 Toolkit, which is based on ViaCrypt's older code. The toolkit knows about all the features in the message formats, so even if the application programs from PGP don't provide a given friendly or hostile feature, you can still write it yourself, and so can the Bad Guys. 2) PGP 5.* message format - unchanged - uses the multiple recipients, without any indication of or dependence on relationships between the recipients. The format is approximately Recipient Record 1 - KeyID1, E(sessionkey, PubKey1) .... Recipient Record N - KeyIDN, E(sessionkey, PubKeyN) Message - E(Message, sessionkey) KeyID is the 32-bit KeyID, rather than a fingerprint. I don't know if the format or the PGP 5.x software can generate or accept messages with recipient records for two different keys with the same keyid (or whether it matters if the keys are for DH*, RSA, or both.) * DH can be spelled "E L G A M A L" -- Blame Cylink :-) While 5.0 did introduce new data formats, they're not stealthy, and features like the SMTP filters depend on being able to know how many recipient-key records a message contains, where their boundaries are, and what their KeyIDs are. 3) PGP 5.* public key format - The 5.5 features are actually present in the 5.0 key record formats, but there wasn't any implementation that used the extra fields. The record for keys is about like this, though I may have some of the details wrong. The record for the RSA Keys uses the old format; this format is for newer keys. Key Record type KeyID UserName Algorithm ID - the interesting combo is ElGamal and DSA Encryption Key OptionalCMRK_1: (Mandatory/Optional flag1, Msg Recovery KeyID1) ..... OptionalCMRK_N: (Mandatory/Optional flagN, Msg Recovery KeyIDN) (Note: the format allows multiple records, PGP5.5 only generates one, though it might accept and use multiple. Nobody indicated whether more than one CMRK indicates that the sender should encrypt to all CMRKs, pick one, or do something interesting like secret-share.) (Note: the KeyID is a 32-bit KeyID, not the full fingerprint, which has amusing deadbeef attacks. (Unless I remembered wrong.)) Signature Key Self-Signature on (Encryption Key, Signature Key, UserName) (I don't know if the self-signature includes the CMRKs, but I think it includes the user names.) Optional_Signature_1: (Signature KeyID1, Signature1) ..... Optional_Signature_N: (Signature KeyIDN, SignatureN) (I don't remember if it's just the KeyID or the full fingerprint.) (Note: Signatures are only on the signature key, so you can change the encryption key and keep your collection of web of trust signatures; this is secure because the encryption key is signed with YOUR sig key, and your sig key is signed by your friends' sig keys.) The signature structure is interesting, since it lets you implement forward secrecy somewhat conveniently - just change your encryption key. I don't know if the 5.0 / 5.5 implementations can easily handle multiple records for the same KeyID, so there may be some transition issues, but that's an implementation question, not a data format question. The CMRK** is obviously the new and controversial feature. The key is attached to the recipient's key, not the sender's program, which has some implications in who has to participate in any message escrow activities and where they take place. To some extent this is planned, and to some extent it's just the consequences of what parts of the system you have control over and what you don't. This approach has the recipient publish a CMRK KeyID, and has the sender decide whether to use it, rather than having the sender's system specify who gets the CMR copy. - Since this is the data format, it doesn't have any control over what the sender really does; any enforcement is in the sender's or recipient's client or in the SMTP mail filters. - The format just contains the CMR KeyID, not the key itself; looking up the key is a separate job. (** Corporate Message Recovery Key? Cover My Rear Key?) NOT TALKED ABOUT, but possibly relevant: www.pgp.com says: "Using PGPs Administrative Wizard, for example, administrators can set key generation configurations; require encryption for all email messages sent by a set of users; enable corporate message recovery; and limit the ability of users to perform certain actions, such as key generation." I assume the parts about key generation are limitations on the client, either generating PGP Crippleware? It can't be that heavy a restriction, since users could use PGP5.0, or 2.6.2 if the rest of the company can accept RSA keys, but it's sounds disturbing and it would be nice to see documentation. Could it be limits in the keyserver instead? Also not talked about - CERTIFICATE SERVER, and CERTIFICATE SERVER REPLICATION ENGINE which has lots of cool LDAP directory lookup stuff. The web page didn't say anything about policy administration on the server, but it's another obvious hook, assuming people in a company use it (e.g. a key server could only store keys with CMRKey set to Mandatory, though I don't know if the initial PGP CS version does that sort of thing.) 4) PGP 5.5 Implementation and GUI - - When you generate a 5.5 DH key, you have the option of specifying a CMRK and setting the Mandatory/Optional flag. I don't remember if there's an option to force you to use the CMRK, or to set a default CMRK or default value for the Mandatory flag, but the PGP folks kept saying things about always asking you things and always letting you know when it's going to do things. - The PGP 5.5 implementation puts at most one CMRK in the record, though it doesn't choke on receiving multiples. - If you receive a key record containing CMRKs, PGP 5.5 stores them; I don't remember if it alerts the user at that point or only when the user uses the key later on. - If you encrypt a message using 5.0, it ignores the CMRK. - When you are encrypting a message, the GUI lets you pick what keys to encrypt to. If one of the keys has a CMRK, if the Mandatory flag is not set, it asks if you want to set the CMRK as a recipient. If the Mandatory flag is set, it puts the CMRK as a recipient. Either way, you can delete the recipient, and it doesn't enforce it, and it also makes the CMR keys show up in red etc. It will nag you if you delete a mandatory, but won't stop you. (I think I got those details right.....) Also, if there's a CMRK KeyID, and your keyring doesn't contain the key for that KeyID, it asks if you want to fetch it from the keyserver. - As far as I remember, if you have a CMRK Mandatory set on one of your keys, and you receive a message addressed to your key, it doesn't check if the message was also addressed to your CMRK. A Bad Guy could build an implementation that did this, but the messages are interoperable with PGP 5.0 and don't contain any indication that any recipients use or are CMRKs, so it's easy to work around if they do. And a Bad Guy could also build in Passphrase Leakage or other evil things anyway. Again, the CMRK belongs to the recipient, not the sender, and deciding to encrypt to it belongs to the recipient. The ViaCrypt BusinessGAK version had a feature that let you compile in a Message Recovery Key that the sender was forced to use (which was a clone of the Always-Encrypt-To-Self code.) This is #defined out in both 5.0 and 5.5; the PGP folks tried to see what happened if they #defined it in when compiling, and it nicely dumped core when they used it. 5) SMTP filters - PGP Policy Management Agent for SMTP is really separate programs for Incoming and Outgoing mail. None of the PGP 5.5 features do more than nag you about using them; they don't have an enforcement mechanism. The SMTP filters, on the other hand, are designed for enforcement, and some of the interesting security and control issues come from the interaction between the filters and the PGP5.5. The PGP folks said that their particular implementation was a quick and basic job using the toolkit - so even though it's not particularly draconian or intrusive, it's easy for people to write their own that are more hostile. Neither filter, for instance, saves copies or forwards copies of mail to an archive or corporate enforcers or runs scripts - all they do is pass or bounce the mail (with configurable message). But you could write one that did, if you were that type of company. Source is not provided ("Look, we have to have _something_ to sell"), but some of the toolkit example code will be fairly similar. The filters don't look inside encrypted packets (so they don't have to manage private keys or other dangerous things). This does mean that they can check for encryption or signatures, but can't check if there's a signature inside an encrypted message. 6) Incoming SMTP filter - Really simple Remember - CMRKs are attached to the recipient, not the sender; this is the only place you can enforce that for your employees. Incoming mail is checked to see if it's acceptable, and either passed to a "real" SMTP server or bounced with a message (typically includes a policy statement or URL and/or a pointer to a key server handling the CMRKs.) Note that all the filtering is based on KeyIDs - not email senders or email recipients or transport info. Messages can be rejected if they're unencrypted, or rejected if the encryption recipients don't include one of a set of keys. Unless I'm remembering wrong if the list of keys was not dependent on the recipients, so you can't do things like "If Recipient=PurchasingClerk Require PurchasingBoss", though you can require "One Recipient in set PurchasingBoss, SalesBoss, EngrBoss", etc. Unfortunately, this pushes the company toward using one CMRkey, since it's not very flexible, though it can easily handle multiples. There may have been an option to accept signed mail, or that may have only been in the Outgoing SMTP server. There wasn't an option to reject unencrypted mail. (You could probably fake this by accepting unencrypted messages while also requiring encrypted messages to include a recipient whose key is not published anywhere and not publishing that keyid so nobody runs a deadbeef attack on it. I haven't verified this...) There wasn't an option to email a copy to the archive; you could write your own, but presumably any site that wants to save copies of all encrypted messages is already saving copies of all unencrypted messages already. Or they're really only making sure there's a CMRKed copy of the session key so they can decrypt the message on the late recipient's disk after he gets hit by a bus or a subpoena. 7) Outgoing SMTP filter - more complex. IF Sender_IPaddr in LIST, Evaluate RULE (parameter KeyIDList) -> -> Accept (fwd to SMTP server) OR Reject with parameterized bouncemessage. You only get one list of IP addresses, and you can only accept/reject, but the rulesets are flexible, and you can chain multiple filters together (the filter can run on Port 25 but can also run on other ports, and can forward to an SMTP server on other ports, so you can stack a bunch of these on a single box and chain them together.) Note that this doesn't look at the sender's or recipients' email addresses, just the sender's IP address. This is sometimes limiting (consider mail servers with multiple users, or multi-user machines, or people who do multiple functions from one machine), but it's more secure than trusting easily forged information like the sender and sender's address. A fancier system would include these in filtering capability. That capability may have been left out on purpose, or it may just be limited development time. (I don't remember if you can use multiple rulesets, but you can stack.) I also don't remember all the possible rules, but this is close: - Require Encryption (yeah!) - Require Encryption to Key on KeyIDList -- remember that CMRKs are attached to recipients' keys, not to senders' keys or mail packages, so the senders have to include any required keys themselves unless the recipients' CMRK keys are administered jointly with the SMTP server. (Sending them enough bounce messages may give them a hint, but the sender's PGP5.5 system won't do it automatically.) Thus, it's easy for CompanyA BuildingA to make sure that messages to CompanyA BuildingB employees are encrypted to one of CompanyA's CMRKs, but it doesn't have a clue about CompanyB's CMRKs or RandomRecipient's CMRKs, though if the recipients put their keys and CMRKs on some public keyserver a more sophisticated (and slower) SMTP gateway could check. - Require Signature (Remember that it can't look inside encrypted messages, so it only does this for unencrypted signed messages.) - Require Signature from KeyIDList - since this ruleset is used along with IP address lists, you could require things like "All email from Purchasing's machines are signed by Purchasing" "All email from the PR department is signed by the Marketroid Key" "All email from PR users is also signed by someone technical" :-) "All email from technical people is signed by Corporate Security" :-( "All email from the company president's key is signed by PR and Legal" (Note that this doesn't let you say "All email purporting to be from the company president" since it doesn't read email headers.) "All mail from the company president's real key is signed by the company president or her secretary" - Block encrypted mail, block signed mail (I think both of these were there, and if they weren't, you could implement them by some combination of features.) - Clear Text - you can allow this or block it. Storage Keys vs. Signature Keys vs. Message Encryption Keys - As described above, PGP5.* does use separate keys & algorithms for signatures and encryption, except for the old RSA keys. Storage Keys are a different issue - the main distinctions between storage keys and message encryption keys are - storage keys are used by the owner, while message encryption keys are used by someone other than the owner for items that will be given to the owner. - storage keys are useful when you have the storage media, message encryption keys are useful when you have a copy of the message, either legitimate or eavesdropped. - message encryption cyphertext gets mailed; stored cyphertext just sits there :-) PGPdisk is a pure storage key system, and perhaps there would have been less political furor if PGP had done Corporate Storage Recovery Keys, but it's not a mainstream product for PGP Inc., and only runs on Macs. Doing the storage job right means integrating with backup servers (disk drives get crashed or scribbled far more often than employees get hit by trucks...) which isn't PGPInc's specialty. In reality, users often use PGP for storage, including for messages they've received (depending on their mail GUI) and for files on disks (encrypted to themselves.) File-by-file encryption is easier to back up securely than whole-disk encryption, which requires either dumping the whole disk to backup media or copying to the backup in the clear. The latter is especially useful if the backup server is also an encrypted storage system, but the copying may be a security risk, unless you do really fancy things, and there's the whole question of whether the backup storage is encrypted with the same keys as the primary (hit-by-truck risk) or with a different key (corporate message access equivalence risk.) Business environment and documentation - [Mostly non-technical] PGP is a real business. They've got deadlines, they've got accountants, they've got people beating them up to ship code by the end of the quarter so they can bill people, they've got customers telling them they won't buy stuff until they get Feature X added or removed, all the usual stuff. The design consultants who used to do their export controlled web site left them a maze of twisty little CGI scripts, all different, so getting actual technical documentation out has taken far more work than anybody had time to do before a release date. (Some documentation is claimed to exist :-) Their SMTP packages could have had far more features, but they felt this at least minimally met their requirements, and there was some thought toward extensibility. While 5.0 did introduce new data formats, they're not stealthy, because they haven't seen much (any?) paying-customer demand, and features like the SMTP filters depend on being able to know how many recipient-key records a message contains, where their boundaries are, and what their KeyIDs are. So they recommend that people who want stealth go work OpenPGP and build formats that work to pressure PGP Inc. into using it. One of Phil's goals had been to design a system that provided the business message recovery features their customers were asking for without providing access to users' private or signature keys, as a counter-argument to the GAK advocates who claim they need it. [ As might be expected, much heated discussion occurred on this issue. :-) ] Some things that time pressure makes it difficult to think about, or at least implement, beside stealth, are features like secret-sharing the session keys to CMRKs (it's not possible to do this cleanly, without affecting a bunch of other things), or making session key recovery a difficult and slow process so it doesn't get done often (e.g. zeroing the bottom N ~ 32-40 bits of session key so recovery requires some brute force as well as the keys.) Building in the ability to crack messages using a single master key is really bad (though at least it can be a different master key per user or per message); perhaps when 5.6 or 6.0 handles multiple CMRKs it will implement them by secret-sharing rather than making them each full recipients. - Customers - Some of the customers do want to "recover" all their users' traffic. Others wanted to make sure that mail to a customer service rep got encrypted to the other customer service reps also, or at least to the rep's boss, so someone could handle the business if the original recipient was away. One of the more obnoxious customers was implementing CAK by having the Corporate Security department generate keys and hand them to the users on floppies; this gives them a less obnoxious approach that they're willing to try. One of the customers was really paranoid about making sure their employees didn't leave their CAD drawings encrypted and then steal them or extort money from the company for decrypting the plaintext when they quit; apparently the idea of using a document management system like programmers use for source code control had never occurred to them.... Thanks! Bill Bill Stewart, stewarts(a)ix.netcom.com Regular Key PGP Fingerprint D454 E202 CBC8 40BF 3C85 B884 0ABE 4639

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