On Wed, Oct 03, 2007 at 09:45:30PM +0200, G?bri M?t? wrote: > > A service will gather data in a database and this data has to be signed > and timestamped for security reasons, and the archives of these data are > also need to signed and timestamped. The data will be used for internal > purposes, so another internal server can issue the signs and stamps. >
OK. This service gathering the data: is it your own dedicated server or is it an external service provider. Assuming that you don't controll (in a security sense) the database itself (if you did, why bother with this?). If I understand correclty: Database the data-gatherer can query. You set up a dedicated, physically secure box and provide it with a secure source of time (GPS?). Assuming that you don't want the latency for them to email the box a hash, have the box append a time stamp, sign it, and mail it back. You need a dedicated channel from the time server to the data-gatherer of latency low enough to meet the time-stamp requirements. Do you need to send the timestamp back to the data-gatherer or will they be sending the data to you by a slower method? You could either write a dedicated server or set up a lpd hack. They gather the data, tarball it, take a hash and put it in an index file (like an MD5SUM file in an ftp archive). They send a file containing only the hash and the unique tarball file name to the lpr on the time server. A dummy spool there hands the file to a 'filter' that takes that file, extracts the md5sum, file name, appends the time, and appends that whole line to a file. For hard copy, each line could be printed to dedicated dot-matrix printer as it is generated. Or your time server is running a database and the data-gather can issue the SQL insert query directly and the database system itself fills in a time-stamp field. Doug.
