On Thu, Apr 03, 2003 at 04:04:43PM -0500, Blaise St-Laurent wrote: > the more i think about it though, the less i think that database + > tamper resistance is going to be an syslog issue. If you want to sign > or at least put a checksum against every line that goes into your db, > the best way i could think of doing this is to write a trigger on > insert that calculates the checksum based on the values you supply > (time, server, msg etc..) and adds it to the appropriate column. I'm I may be showing my ignorance here, but can someone explain to me how checksums *by themselves* actually "prove" the data hasn't been tampered with? I mean, if I have a years worth of syslog data, md5 checksum the files, and burn them all off onto tape. A year later in court, I can confidently say that the syslog data *as it is on the tape* is as valid today as it was *when the tape was written* (as the checksum will hopefully match). I mean, as far as legal goes, surely all that this checksumming does it "prove" the data hasn't been altered *since it was written*. It doesn't say anything about me fiddling with it before I checksumed it... Surely in court, it's simply about proving your copy of the data hasn't been altered since it was written, and then it's *totally* a "reliability of the witness" type problem after that...? Similarly, if you have some nice proprietary "logging server" that can take input from syslog clients and it puts it into a checksummed database you can't fiddle with as you don't know how it works, then you can still input bogus data can't you... I don't understand why this issue is always shown off as being a technical issue, when it court is usually ends up being a "people issue" (i.e. do they trust you)? -- Cheers Jason Haar Information Security Manager, Trimble Navigation Ltd. Phone: +64 3 9635 377 Fax: +64 3 9635 417 PGP Fingerprint: 7A2E 0407 C9A6 CAF6 2B9F 8422 C063 5EBB FE1D 66D1 _______________________________________________ LogAnalysis mailing list LogAnalysisat_private http://lists.shmoo.com/mailman/listinfo/loganalysis
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