On Sun, 14 Apr 1996, Chris McAuliffe wrote:

While not paying attention, Jeremey Barrett <jeremey@forequest.com> wrote:

...

crypt() is a hash function, and hence is not subject to export restriction. (To my knowledge).

crypt(3) is a library routine implementing a hash function. Crypt(1) is a general purpose cryptography program implementing an algorithm similar to an enigma rotor machine. My question stands.

Ah. My mistake... the man page I have on crypt(1) says this: RESTRICTIONS This program is not available on software shipped outside the U.S. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Jeremey Barrett Senior Software Engineer jeremey@forequest.com The ForeQuest Company http://www.forequest.com/ "less is more." -- Mies van de Rohe. Ken Thompson has an automobile which he helped design. Unlike most automobiles, it has neither speedometer, nor gas gage, nor any of the numerous idiot lights which plague the modern driver. Rather, if the driver makes any mistake, a giant "?" lights up in the center of the dashboard. "The experienced driver", he says, "will usually know what's wrong." -- 'fortune` output

Did the library include other encryption functions, other than one-way functions? If so, I could see it being restricted. Linux, which is freely available anywhere, includes a DES-using crypt() one-way hash. But since a one-way hash function (implemented as a one way function) can't really be used for encrypted communication, I don't think it is subject to export restriction. On Sun, 14 Apr 1996, Dan Busarow wrote:

On Sat, 13 Apr 1996, Jeremey Barrett wrote:

...

crypt() is a hash function, and hence is not subject to export restriction. (To my knowledge).

SCO (and Novell, when it was selling Unix) both shipped libcrypt.a as a seperate product in their development systems. Only US and Canadian customers are allowed to buy the library. Programs statically compiled with libcrypt appear to be OK, but furineers can't have API access to this technology :)

Dan -- Dan Busarow DPC Systems Dana Point, California

-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Jeremey Barrett Senior Software Engineer jeremey@forequest.com The ForeQuest Company http://www.forequest.com/ "less is more." -- Mies van de Rohe. Ken Thompson has an automobile which he helped design. Unlike most automobiles, it has neither speedometer, nor gas gage, nor any of the numerous idiot lights which plague the modern driver. Rather, if the driver makes any mistake, a giant "?" lights up in the center of the dashboard. "The experienced driver", he says, "will usually know what's wrong." -- 'fortune` output

Jeremey Barrett <jeremey@forequest.com> writes on cpunks:

[...] But since a one-way hash function (implemented as a one way function) can't really be used for encrypted communication,

One way hashes can be used to produce an block encryption system running in CFB mode, eg: Peter Gutmann's MDC. (CFB mode is where you encrypt an IV (just a random salt) with the key, and XOR the result with the data (you chaing the encrypting for subsequent blocks) -- to decrypt you just repeat the process, use the same IV and encrypt again. As you never actually use the block ciphers decrypt function, you can therefore (and this is what MDC does) use a one way hash in the place of a block encryption algorithm in CFB mode.)

I don't think it is subject to export restriction.

They don't seem to be subject to export restrictions, but then perhaps that is paradoxical, perhaps they should be. (Well no crypto should be export restricted in my view naturally, but for logical consistency you understand...) It would in my view be a good thing if one way hash functions were declared to be non-exportable, as this would clearly hinder commerce, as they are used in signatures and authentication. Also I seem to remember that Dan Berntstien's case was based on the prior restraint in him not being free to discuss his method for turning a one way hash into a symmetric key function. Adam -- Exported RSA today? --> http://www.dcs.ex.ac.uk/~aba/rsa/ #!/bin/perl -sp0777i<X+d*lMLa^*lN%0]dsXx++lMlN/dsM0<j]dsj $/=unpack('H*',$_);$_=`echo 16dio\U$k"SK$/SM$n\EsN0p[lN*1 lK[d2%Sa2/d0$^Ixp"|dc`;s/\W//g;$_=pack('H*',/((..)*)$/)