December 2003 - cypherpunks-legacy

(none)
by Jeff Gostin 17 Dec '03

17 Dec '03

Blanc Weber <blancw(a)microsoft.com> writes: > who cypherpunks Good question, although it isn't the greatest english... :-) A wise man said cypherpunks assume privacy is a good thing. They are devoted to cryptography. They love to practice playing with public key cryptography and anonymous mailers. They write code. They don't care if you like the software they write. So, that's "who cypherpunks". :-) --Jeff -- ====== ====== +----------------jgostin(a)eternal.pha.pa.us----------------+ == == | The new, improved, environmentally safe, bigger, better,| == == -= | faster, hypo-allergenic, AND politically correct .sig. | ==== ====== | Now with a new fresh lemon scent! | PGP Key Available +---------------------------------------------------------+

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Re: RemailerNet
by Jonathan Rochkind 17 Dec '03

17 Dec '03

Part of our disagreement/misunderstanding might be in differing conceptions of the form the remailer net should take. > There should be two anonymous IDs, one for sending, one for > receiving. You seem to be talking about a Julf-style anon system, where the system knows who you really are. If the system is corrupt, if Julf were an NSA agent, then the entire system is compromised and useless. I like the cypherpunks remailer concept better, where each link in the chain only knows the next link in the chain, and security is achieved by multiple links. If several of the links are actually NSA agents, your security is reduced, but not compromised completely. If you've got a chain of, say 10 links, even if 7 of them are evil NSA agents, you still can probably retain your anonymity. Return addresses are accomplished by encrypted "resend-to:" blocks. It seems much preferable to have a system where it isn't neccesary to trust any one net entity completely, as it is in a Julf-style anon-ID system. [Of course one could use a combination of both in communications too, but I wouldn't feel safe unless my anonimity was safe even if the Finish FBI raided Julf's site.] When looked at with this goal in mind, I think maybe the newsgroup as a method of passing remailer net information makes a bit more sense. I don't think the possibility of the newsgroup being spoofed is actually fatal to the system. Let's examine ways in which it could be attacked: 1) The Enemy could introduce completely made-up "i'm here" messages, pointing to non-existent remailers. This doesn't harm anything at all when combined with a "ping"ing of remailer sites, as I've suggested. (One idea would be just to periodically mail all your remailers with the resend-to: being yourself, to make sure they exist, and are forwarding mail at least some of the time). 2) The Enemy could announce his own Evil-remailers to the net. These remailers would in fact exist, but would do evil things designed to compromise the net. What could they do? They could publicize all messages they get. Again, as long as you have 3 or 4 non-evil remailers in your chain, this doesn't really compromise your anonymity. You can decrease the risk further by only using remailers whose announced keys were signed by a trusted source. The evil-remailer could also just drop all communications in the bit bucket. This doesn't compromise security, but does make the remailer net unusable. By periodically pinging the remailer sites as I've suggested above, this risk can be minimized. If you've pinged the site 25 times, and all 25 times the remailer has forwarded your ping back to you, then odds are that it isn't dropping any messages in the bitbucket. (remember, the evil-remailer can't tell the difference between your ping a a normal remailer message, if done correctly.) 3) The Enemy could intercept announcement messages from good remailers, and replace their public key with his own. He could then intercept all mail to this good remailer, and read it, and forward it on, or drop it in the bitbucket. Using web-of-trust for signed remailer keys should help minimize this risk. 4) Denial of service: The enemy could intercept the announcement messages, and keep them from getting to the newsgroup. This doesn't compromise the security of the net at all, but is annoying. I can't think of any way to avoid this risk, but I think it might be acceptable, because it doesn't actually compromise any security, and would be fairly dificult for the enemy to do for long without being detected. 5) The enemy could intercept announcement messages from good remailers, and replace both the public key and address with his own. This is really just a combination of several of the previous attacks, nothing new.

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A Helpful Tip for Impatient Souls
by Tommy the Tourist 17 Dec '03

17 Dec '03

Those wishing perhaps the ultimate in Cypherpunks ease-of-use and greatest peace of mind, may find it useful to simply delete everything that does NOT come from one of the following email addresses: tcmay(a)netcom.com frissell(a)panix.com sandfort(a)crl.com Additionally, you'll probably want to let through posts from Hal Finney, Eric Hughes, and Bruce Schneier, but I forgot their addresses off-hand and am much too lazy to look them up. :) If you're using the "ELM" mailer, you can do this by creating a file called filter-rules in your .elm directory, containing the following text (more or less): if (from contains "sandfort") then save "~/cypher" if (from contains "frissell") then save "~/cypher" if (from contains "tcmay") then save "~/cypher" if (to contains "cypherpunks") then delete Add additional addresses as needed, but be careful of excessive alliteration. ------------ To respond to the sender of this message, send mail to remailer(a)soda.berkeley.edu, starting your message with the following 8 lines: :: Response-Key: the-clipper-key ====Encrypted-Sender-Begin==== MI@```&]^&2?(E<U9BPG1]W7L;=*KH_R`E[:HLL5(1[#C?F1F@+XOR[*O4;Q* M5#7=J!((PXPB/`Z?E75=RY`'42E\')B98SJ<!]_D6):*2C`'_S7T,&Y7VY1R :GOR712QF!VS=527/-L\@>E6`)=?D_W1Y'5P` ====Encrypted-Sender-End====

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latency
by merriman＠metronet.com 17 Dec '03

17 Dec '03

Looks like we had a little latency of our own on the list the last couple of days. Anyone know what happened? Dave Merriman -----BEGIN PGP PUBLIC KEY BLOCK----- Version: 2.6 mQCNAi3uZ2MAAAEEALWQtxX77SZSaFls6cVbPp+fZS4MNyKK3ZFYQo0qWyj+0tMq YgRTPRJRaCQixo63RttknogfPp514qdVMZw5iPeOXmD+RxrmTTwlbGqA7QUiG1x5 LG2Zims5zk4U6/rt8hwLh0/8E4lIb9r5d31qc8L1A9Twk/cmN8VrTvyYOzAZAAUR tClEYXZpZCBLLiBNZXJyaW1hbiA8bWVycmltYW5AbWV0cm9uZXQuY29tPokAlQIF EC3uaE3Fa078mDswGQEBbI8D/0FiwDcbfeNyDVJ+7EIWHjIxVkIGu+ArYUEllR3G SBHVZ9Vh7n8bNXeNHMnG5cZ23TLMVvweyhxFS+cDi+I7omeDNr6x65z500LxfUvL K5bSuSiBVkTp2z+/iojY/662JwKHzEEunuJ4CO8Yhxy11CdeszEX7DpXzRxLL92r EmO2 =4ZfP -----END PGP PUBLIC KEY BLOCK----- Finger merriman(a)metronet.com for PGP2.6ui/RIPEM public keys/fingerprints.

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Re: RemailerNet
by jdd＠aiki.demon.co.uk 17 Dec '03

17 Dec '03

In message <199408051528.LAA18523(a)cs.oberlin.edu> Jonathan Rochkind writes: > You seem to be talking about a Julf-style anon system, where the system > knows who you really are. If the system is corrupt, if Julf were an > NSA agent, then the entire system is compromised and useless. If you are using unmodified Internet hardware and TCP/IP as the underlying transport system, then your point of entry into a remailer network definitely knows which machine is originating a message and the point of exit definitely knows where it is going. If your transport system is the email system, the same holds true because email runs on top of TCP/IP. While fiddling with email headers may make you feel secure, it gives you no protection. It is a large project (say 30,000 lines of code, some of it at the kernel level) to build a remailer network which does not use SMTP and TCP/IP. >From the scale of efforts that you are talking about, I assume that you do not intend to do this. So the remailer gateways know the source and destination addresses, they know your electronic identity. This may or may not lead them to your physical identity. That can be concealed fairly easily, especially in large institutions with poor control over their network resources. But this has nothing to do with our discussion now. > I like the cypherpunks remailer concept better, where each link in the chain > only knows the next link in the chain, and security is achieved by > multiple links. If several of the links are actually NSA agents, your security > is reduced, but not compromised completely. If you've got a chain of, say > 10 links, even if 7 of them are evil NSA agents, you still can probably retain > your anonymity. Return addresses are accomplished by encrypted > "resend-to:" blocks. It seems much preferable to have a system where it > isn't neccesary to trust any one net entity completely, as it is in a > Julf-style anon-ID system. [Of course one could use a combination of both > in communications too, but I wouldn't feel safe unless my anonimity was > safe even if the Finish FBI raided Julf's site.] Promiscuity leads to infection. Each contact with a new RemailerNet gateway increases the probability of your being compromised. If you modify the proposed RemailerNet to allow reposting at gateways, you have all of the benefits of the system described above, without the risks. Reposted messages would be encrypted with the far gateway's public key. The near gateway would then have no idea of the ultimate destination of the message. In a well designed system, the far gateway would also not know the identity of the sender. > When looked at with this goal in mind, I think maybe the newsgroup as a method > of passing remailer net information makes a bit more sense. > > I don't think the possibility of the newsgroup being spoofed is actually > fatal to the system. Let's examine ways in which it could be attacked: > > 1) The Enemy could introduce completely made-up "i'm here" messages, pointing > to non-existent remailers. ... > 2) The Enemy could announce his own Evil-remailers to the net. These remailers > would in fact exist, but would do evil things designed to compromise the net... > 3) The Enemy could intercept announcement messages from good remailers, and > replace their public key with his own. ...He could then intercept all mail to this > good remailer, and read it, and forward it on, or drop it in the bitbucket. > 4) Denial of service: The enemy could intercept the announcement messages, and > keep them from getting to the newsgroup. ... > 5) The enemy could intercept announcement messages from good remailers, and > replace both the public key and address with his own. This is really just a > combination of several of the previous attacks, nothing new. In the early to mid 1950s the FBI set out to penetrate Communist Party USA cells. At some point, when the fear of the Red Menace began to recede, people began to talk. The communists said, "you could always tell who were the FBI agents. They were the ones who paid their dues." The FBI was actually providing most of the funds for CPUSA. If anyone cared enough, what they would do is (a) put up enough remailers so that they were, say, a steady 80% of those announcing in the alt.x group; (b) provide a good, reliable service nearly all of the time; and (c) drive the other 20% out of business with a steady disinformation campaign (rumors, complaints, etc) and other more aggressive tactics. The FBI types running (a) and (b) would be well funded and they would be the sort of steady, unimaginative people who run small businesses well. The CIA field agents masterminding (c) would be very well funded network freaks, some of them ex-hackers. They could operate outside the USA and pay little or no attention to US laws. Pity the poor 20% in the face of such attacks. Any traffic sent through this remailer network would have only a tiny chance of getting through without being compromised. If you picked 5 remailers, the chances of all being non-FBI would be about .2^5, 3 in 10,000. The other 9,997 messages would be copied immediately to Langley. The proposed RemailerNet could be attacked in much the same way. But if the network were widely distributed so that gateways were in different legal jurisdictions and different countries, and if most of the people involved knew one another, it would be more difficult to compromise it. -- Jim Dixon

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fast 386 DES code figures
by Phil Karn 17 Dec '03

17 Dec '03

To see if software DES could really be made acceptable in a IP security protocol, I've been bumming cycles out of my old DES code. I've completely translated the encrypt and decrypt routines to assembler, with no calls or jumps inside either routine. I picked up Richard Outerbridge's seriously clever initial and final permutation algorithm from Schneier, along with a few of his other tricks. The bottom line: about 38,373 encryptions/sec (2.456 megabits/sec) on a 50 Mhz Intel 486 running in 16-bit real mode. This includes the overhead of the C loop that calls the encrypt function and prints a status line every 10,000 loops. The code would probably run faster if assembled and run in 32-bit native mode, as this would eliminate a lot of 1-clock operand size prefixes (I do many 32-bit operations). Oh, by the way, if I eliminate the permutations the speed goes up to about 42,986 encryptions/sec (2.751 megabits/sec), an increase of about 12%. That says I should be able to do triple-DES at about 13,777 blocks/sec (881.7 kbit/sec) although I haven't tried it yet. What still bugs me is that Schneier lists the speed of one commercial DES implementation as 40,600 encryptions/sec on a 33 Mhz 486. I just don't see how that's possible without using a lot more memory for lookup table space (I use only 2K, which is nice in a DOS environment). In any event, this should be enough for a T1 link (half duplex) as long as too many cycles aren't needed for things like routing packets. :-) Phil

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Re: Remailer ideas
by jdd＠aiki.demon.co.uk 17 Dec '03

17 Dec '03

In message <9408051709.AA14763(a)ah.com> Eric Hughes writes: > Jim Dixon analogizes between the Internet and remailer networks. The > analogy has some merit, but yet breaks down badly with the very first > point: > > * all packets should be acknowledged > > This is not the way the Internet works. There are some problems with vocabulary here and some conceptual problems. The objective is a system which is highly reliable and resistant to traffic analysis. If you have three messages in, one 10 bytes long, one 1000 bytes long, and one 1,000,000 bytes long, and you send them out to three different destinations, it does not take genius to see which is which, no matter what order they are dispatched in. But if you send them out as packets, each say 4096 bytes long, with all packets acknowledged, and the routing of the packets is random, and noise has been introduced ... traffic analysis is very difficult. TCP/IP is designed to work in an environment which is unreliable but also unhostile. The sliding window algorithm and acknowledgement at the message level is suitable for that environment. TCP/IP has been optimized for speed. [stuff omitted] > Further, in email, there's currently no notion of a connection. The internal functioning of RemailerNet is not the same as the functioning of the email system. All RemailerNet communications are reliable. Packets are acknowledged and the acknowledgement includes a hash of the packet contents, so that the packet cannot be tampered with. Acknowledgements will in general take different routes from packets. > * users should communicate with trusted gateways > > This point is only half true, because the analogy only subsumes one > kind of trust. For remailers there is both trust in delivery and > trust in silence, the destruction of the message and information about > it. 'Trust in silence' is a good term. This can be enhanced in a number of ways. If you are corresponding with someone you know, you encrypt your messages. If you are corresponding with a stranger, you encrypt your message with the public key of a far gateway; then post it to the far gateway through a near gateway. The near gateway knows who is sending, but cannot read the message and does not know the destination. The far gateway decrypts the message before delivering it, so it knows the message and the destination, but not the sender. If you are sufficiently paranoid, you put your message inside yet another envelope, mailing it through the near gateway to a far gateway, which posts it on to another gateway, which finally posts it to its destination. Remailer gateways should be spread very wide geographically if the network is to be secure. If you are very concerned about anonymity, bounce a message through gateways in, say, the USA, Finland, Russia, and Ireland. If your concerns are about your employer, say, the probability of his getting at four different gateways in four different jurisdictions simultaneously is vanishingly small. If your concerns are about governmental authorities, they are not that much higher. -- Jim Dixon

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Re: Remailer ideas (Was: Re: Latency vs. Reordering)
by jdd＠aiki.demon.co.uk 17 Dec '03

17 Dec '03

In message <199408061404.KAA02300(a)cs.oberlin.edu> Spencer Mullen writes: > Jim Dixon writes: > > >Commercial remailers would probably be very concerned with legal > >issues, both criminal (pornography, etc) and non-criminal (copyright > >violations). > > It would seem that remailers shouldn't be anymore accountable for > passing on illicit pornography than the postal services are today. I really do not want to try to argue the legal issues here; I am not a lawyer and claim no expertise. At a practical level, if you were running, let us say, an Internet Service Provider (ISP) and offered remailer services, you would in time attract the business of people who used your services for various unlawful purposes. You could not stop this without going through everyone's private mail. This would itself probably be illegal and certainly would lose you business. I understand that Playboy magazine spends lots of money pursuing people for copyright violations, and that criminal charges have been filed by the authorities in Tennessee or Arkansas against someone in California who sent them pornographic materials over a telephone line. The Post Office has what is called in the UK "crown immunity" against such prosecutions. So do "common carriers" in the USA. They are given special legal status. I do not know, but I believe that the telephone companies are legally common carriers. As a remailer gateway operator, you would probably have to argue things out in court, which could be very expensive. In the case of criminal charges, you would have to expect to lose your equipment for some time, and perhaps your freedom. I suspect that legally the key step would be to never store messages for any period of time. It would be prudent to erase them as soon as their receipt was verified. This would also save disk space, and it would be in line with the 'trust in silence' ethic. I would do this and then publicize the fact that I did so widely. This would discourage public prosecutors, who really don't like to do futile things. And I would incorporate the gateway and make sure it wasn't worth a great deal. This would discourage civil suits; clients get very irritated when they win the lawsuit and find that after all their legal expenses the target has filed for bankruptcy. -- Jim Dixon

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Mandated Forfeiture
by blancw＠pylon.com 17 Dec '03

17 Dec '03

Responding to msgs by: Jim Hart: Thus, the upshot of these so-called "privacy" regulations is to destroy our last shreds of privacy against government, and calm us into blindly getting even more of the details of our personal lives into the mainframes of the major government agencies and credit reporting agenices........ Timothy C. May: . . . . Suffice it to say that our credential-happy society is getting very little real benefit for demanding credentials at every turn and is instead providing precise dossier material for those who keep dossiers. ................................................................. ..... The regulations regarding privacy and the demands for them by the 'credential-happy' society leaves me with the impression that this phenomena has the role of acting as substitute for something, as any time that the voting public makes demands from the big G it indicates a need to compensate for a sense of inadequacy relative to some area of their social co-existence. In this case it is as though the demand for personal information & credentials replaces sensitivity to, & understanding of, human nature. As services become more automated the opportunity for human contact is diminished, while the need to certify the verity of remote data becomes more critical. When the information has been centralized, it has the effect of displacing personal responsibility away from the individual up to the State, as the State becomes the official keeper of the data. And how else could the governors be expected to fulfill their obligation of keeping the peace and general welfare, if they cannot gather & keep information on all their remote & moving targets? When the centralized databank gatherers have the required info, then the general populace expects to feel safe that everyone can be dealt with - by their Official Caretakers, sinced it cannot be done by themselves. ("I don't know you, but I can still keep track of you and therefore keep you under control, if you get out of hand.") These things self-perpetuate: the more that one group gives it up, the more that the other takes it up & away; the more inadequate that those who abdicate from responsibility feel, the more they look to their governors to substitute their overriding supervisory powers. The less that the governed exercise their abilities to know themselves and each other, the less capable they become in the art of doing so, and the more convinced they become of the necessity for mandated forfeiture of personal data. When you don't live by reason, you must live by recourse to coercion. Blanc

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Kindness & the Voting Public
by blancw＠pylon.com 17 Dec '03

17 Dec '03

Responding to msg by Doug Cutrell: In the real world, the voting public is not required to be kind to the hospital or the company, either. If a large political block can put into place structures (laws and enforcement) which effectively provide coercion against such denials of service, this is fair play as well. ................................................................. All's fair in love and war. But how many of the voting public does it take to squeeze blood out of a turnip? (i.e. create something from nothing?) Before the voting public which bands together can coerce a service out of some corporate entity, there must first be a Provider in existence. This Provider most probably would not have materialized miraculously out of the good intentions of the State but would had to go through all the time and trouble of gathering the ideas, the resources, and the manpower to make their services available to customers. Once the corporation, that enterprise, that commerical entity, had been created and constructed - once the building was in place, the system set up along with the required equipment, and all of the administrative functions had been set in motion, *then* the voting public would have an object for their attention; they could come together and attempt to take over the operation and coerce the Provider into delivering the benefits indiscriminately to everyone. They could probably even conspire to have this service for free. They might even succeed in accomplishing it, and maybe it would work for a bit. But I don't know how long Providers could survive without remuneration, in the real world, nor how long they would tolerate the image of themselves as Slaves to the Voting Public. Blanc

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