[REBOL] Re: How to generate a UUID? (was possible data format... Re:Re: dbms3.r 01)

2002-01-17 Thread Gregg Irwin
Hi Joel, Thanks for all the info. Great stuff! << Needless to say, none of this implies that synonyms fail to exist (see previous note), but simply that it should be infeasibly hard to construct a synonym for a given input. >> OK, so the only thing we have to do, if I understand things correctl

[REBOL] Re: How to generate a UUID? (was possible data format...Re:Re: dbms3.r 01)

2002-01-17 Thread Brett Handley
> Well, "infeasibly hard" means the probability that a random message > would have the same checksum should be about 6.84227765783589E-49 > and you shouldn't be able to do better crafting one yourself. > > The issue is not that synonyms won't happen, but that they're > unlikely and you can't pred

[REBOL] Re: How to generate a UUID? (was possible data format... Re:Re: dbms3.r 01)

2002-01-16 Thread Brett Handley
I had thought of using checksum/secure as an ID some time back. But the synonym possibility made be nervous. Why? (1) Such a chance is greater than zero (2) I believe that Murphy's law is understated. (3) I've programming so long I'm automatically suspicious of possibilities :) > Needless to say,

[REBOL] Re: How to generate a UUID? (was possible data format...Re:Re: dbms3.r 01)

2002-01-16 Thread Joel Neely
Hi, again, Gregg, Gregg Irwin wrote: > > I don't know if "cryptographically secure" equates to > "universally unique", but I'd be glad if it did. :) > (Should have checked before the previous note...) CHECKSUM/SECURE is represented as being SHA, which does produce a 160-bit "secure" hash of i

[REBOL] Re: How to generate a UUID? (was possible data format...Re:Re: dbms3.r 01)

2002-01-16 Thread Joel Neely
Hi, Gregg, Gregg Irwin wrote: > > Hi Pekr, > > << checksum/secure :-) >> > > I don't know if "cryptographically secure" equates to > "universally unique", but I'd be glad if it did. :) > Absent documentation, who knows (?), but not likely. By the pigeonhole principle, any function that