Strings are internally stored "C" byte arrays. You can even do some traditionally numerical operations on them. 

use MIME::Base64 qw( decode_base64 );

my $scrambled = decode_base64($_);
my $orig      = substr($scrambled, 0, -1) ^ substr($scrambled, 1);

[download]

But if you prefer to deal with an array of numbers, no problem! ord converts allows a character to be treated as a number, and chr does the inverse. 

use MIME::Base64 qw( decode_base64 );

my $scrambled = decode_base64($_);
my @scrambled = map ord, split //, $scrambled;
my @orig      = map { $scrambled[$_-1] ^ $scrambled[$_] } 1..$#scrambl
+ed;
my $orig      = join '', map chr, @orig;

[download]

In reply to Re: Base64 and byte arrays by ikegami
in thread Base64 and byte arrays by joec_

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