-----BEGIN PGP SIGNED MESSAGE----- In <199711252109.WAA05443@basement.replay.com>, on 11/25/97 at 10:09 PM, nobody@REPLAY.COM (Anonymous) said:
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It would be neat if you could quote people and prove that they signed the particular paragraph quoted without supplying the entire text. Is there a way to do this? (It seems impossible, but so does mental poker.)
A crude approach would be to sign every paragraph or line separately, but that's obviously inelegant.
Well this could be done by creating a document signature and then a collection of sub signatures but it can get ugly real quick. What level of granularity does one use for the sub signature? Paragraph: Contentious block of text separated by a line of white space. Line: Block of text ending with a CRLF. Word: Block of text separated by a white space. Then what does the sub signature really tell you? Yes you can verify that the quote was written by someone but it may be taken completely out of context. How about when several blocks of text from different messages are combined. Each individual block checks out but by combining them the text has a completely different meaning than the original document. The best thing right now is for a user to lookup the referring document in the archives and verify the signature. It also give him the advantage of reading the quote in its full context. In an environment where a public archive of messages are not available then other means of obtaining the source document are available (contact the original author, contact the person quoting the original document). In some environments it may be beneficial to attach the original document to the message when sending. Considering that a signed quote would require the Author to format his signatures in this way I for one would not do so nor could I see a reason for doing so. Side Note: The above is in reference to small documents and E-Mail. In large documents it may be desirable to sign every page or sign each chapter in addition to signing the entire document. A case may be made for subsignatures in a E-Mail message in which there are separate signatures for the text of a message and accompanying attachments. In both cases there should be a meta-signature that covers the entire document. - -- - --------------------------------------------------------------- William H. Geiger III http://users.invweb.net/~whgiii Geiger Consulting Cooking With Warp 4.0 Author of E-Secure - PGP Front End for MR/2 Ice PGP & MR/2 the only way for secure e-mail. OS/2 PGP 2.6.3a at: http://users.invweb.net/~whgiii/pgpmr2.html - --------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: 2.6.3a Charset: cp850 Comment: Registered_User_E-Secure_v1.1b1_ES000000 iQCVAwUBNHtZx49Co1n+aLhhAQHXQwQAk7Hp9DvNflJ8ODmixKps9tJuuKM8ARTl fioJxApL+f0xORgcMtfBoD76lCV/heh7KaDO81zg9WfGv7J5bcHHgPv0PTxX8mrx cFxsAX4x+M3meIRNZ2vAEmmy5mKiXNds5y4+w3mgC1/Bi3L4QNGWEqgwPzAehwHn KFwbtj+MY34= =9sOU -----END PGP SIGNATURE-----