This returns 1010001 for your sample input. Is it correct? Is it efficient enough? 
#!/usr/bin/perl
use warnings;
use strict;

use List::Util qw{ sum };

sub ecc {
    my ($hex) = @_;
    my $binary = pack 'H8', $hex;
    my @d = split //, unpack 'B32', $binary;
    my @p = map sum(map 0 + $d[$_], @$_) % 2,
        [ 0, 1, 3, 4, 6, 8, 10, 11, 13, 15, 17, 19, 21, 23, 25, 26, 28
+, 30 ],
        [ 0, 2, 3, 5, 6, 9, 10, 12, 13, 16, 17, 20, 21, 24, 25, 27, 28
+, 31 ],
        [ 1, 2, 3, 7, 8, 9, 10, 14, 15, 16, 17, 22, 23, 24, 25, 29, 30
+, 31 ],
        [ 4 .. 10, 18 .. 25 ],
        [ 11 .. 25 ],
        [ 26 .. 31 ],
        [ 0 .. 31 ];
    $p[6] += sum(@p[ 0 .. 5 ]);
    $p[6] %= 2;
    return join "", @p
}

my $hex = '3E10F67A';
print ecc($hex);

[download]

Update: Added the 0 + which seems to speed up the sub by more than 60%. In a previous update, I used % 2 instead, which caused a speed-up of about 50%.

Update 2: fixed B64 to B32 (thanks LanX).

Update 3: fixed a bug: $p[6] must be % 2 separately from +=, otherwise it can get greater than 1.

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re^3: ECC computation by choroba
in thread ECC computation by savangadi

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