Re: [PHP-DEV] PHP3 and 64-bit land From: sas <email protected>
Date: 02/27/99

On Sat, Feb 27, 1999 at 07:23:51PM +0200, Zeev Suraski wrote:
> On Sat, 27 Feb 1999 sas <email protected> wrote:
>
> > I disagree here. The chance of having the same ptr in 32 bit is about 1 in
> > 2^32 = 4,294,967,296. If you come to Germany, your chance to win the lottery
> > ("6 aus 49") is about 1 to 49!/43! = 10,068,347,520.
>
> Hmm, ok, we'll stay with the Israeli lottery here.

The "extra number" ("Zusatzzahl") doubles the propability. That is still
higher than 1/2^32 ;)

> > It's extremly safe, but you risk random, non repeatable crashes produced by
> > playing that way.
>
> Considering this as a risk is simply wrong. It's more or less like saying
> CRC-32 isn't reliable (there's a difference, but not inherent).

To quote from RFC1510 about CRC-32:

   The CRC-32 checksum calculates a checksum based on a cyclic
   redundancy check as described in ISO 3309 [14]. The resulting
   checksum is four (4) octets in length. The CRC-32 is neither keyed
   nor collision-proof. The use of this checksum is not recommended.

> Either way, you don't risk crashes, at worse, you simply don't find the
> resource you're looking for.

It depends on the data and what you do with it. 

-- 

          Regards,

                            Sascha Schumann | 
                                 Consultant | finger sas <email protected>
                                            | for PGP public key

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