That could result in something larger than 9999 (up to 65535) and it could result in 1, 2, 3 digit pins (you'll never get 0123, but you will get 123).

What's with quotes around variable names?
Why start with the hex form?
Why calculate a hash *and* a checksum?

Using a MD5 hash will produce a good distribution of PINs.
Solution using MD5 hash: 

my $pinc = join('', $data1, $data2, $data3);
my $pin = sprintf('%04d', unpack('N', md5($pinc)) % 10000);

[download]

Using CRC32 will *probably* produce a good distribution of PINs, but I don't personally know that.
Using CRC32 will probably be faster than MD5, but it probably won't be noticeable unless you do millions of these in a row.
Solution using CRC32: 

my $pinc = join('', $data1, $data2, $data3);
my $pin = sprintf('%04d', unpack('%32C*', $pinc) % 10000);

[download]

In reply to Re^3: Need a wait to generate a 4 digit "PIN" number by ikegami
in thread Need a wait to generate a 4 digit "PIN" number by jaiello

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