Suppose someone is asked to provide a long string of random digits, for example:
4866710938572235108576927175549668592830123185576923856998372006958477486523 (just typed on keyboard, not generated in any way)
How good is it expected to be if used as random source?
For example, can I ask someone to think up a list of {1,2,3,4,5,6} numbers and use it instead of a dice (and expect each number to come with p=1/6 knowing the previous numbers).
Is it safe enough to just think up UUIDs without looking for UUID generator tools?
Is there some simple (not requiring any devices or pencil&paper) algorithm to improve "thought up" random sequences?
Update: Trying little experiment as suggested in one comment:
$ xxd -r -p > test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paq8l -4 test Creating archive test.paq8l with 1 file(s)... test 250 -> 270 250 -> 292 $ tail -n +3 test.paq8l | wc -c 272 $ dd if=/dev/random of=test2 bs=10 count=25 iflag=fullblock 2> /dev/null $ paq8l -4 test2 Creating archive test2.paq8l with 1 file(s)... test2 250 -> 274 250 -> 297
Both files (manualy typed and /dev/random-generated) seem to be uncompressible.