A paper wallet is a great way to ensure the longevity of your bitcoins.
If your OS/hardware fails, it will allow you to access your funds.
it is not secure against physical theft.
they could go about securing their paper wallet.
it difficult/impossible to access by unauthorized individuals.
The easiest way for a end user to secure their private key would be to use a easily available tool.
.
If you are more adventurous/concerned you could choose to do custom encryption.
To give a example I will share a excerpt from a open source php script I created when I was young.
// The two functions below borrowed from http://www.phpit.net/code/binary-text/
function bin2text($bin_str) // A function to convert Binary to Text
{
$text_str = ''; // Initilize a blank string
$chars = explode("\n", chunk_split(str_replace("\n", '', $bin_str), 8)); // Split the Binary into groups of 8
$_I = count($chars); // Figure out how many characters there are
for($i = 0; $i < $_I; $i++ ) // As long as a charcter exists
$text_str .= chr(bindec($chars[$i])); // Convert it to binary
return $text_str; // Give the converted text
}
function text2bin($txt_str) // Convert text to binary
{
$len = strlen($txt_str); // Figure out how long the string is
$bin = ''; // Initilize a blank string
for($i = 0; $i < $len; $i++ ) // As long as there are more chars to convert
{
$bin .= strlen(decbin(ord($txt_str[$i]))) < 8 ? str_pad(decbin(ord($txt_str[$i])), 8, 0, STR_PAD_LEFT) : decbin(ord($txt_str[$i])); // Convert them to Binary
}
return $bin; // Give the binary
}
// The two functions above borrowed from http://www.phpit.net/code/binary-text/
function encrypt($txt) // Encrypt the data
{
$mtxt = $txt; // Copy the given data
$len = strlen($txt); // Check the length of given data
$o = array("A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"); // An array with the alphabet
$n = array("A","S","D","F","G","H","J","K","L","Q","W","E","R","T","Y","U","I","O","P","Z","X","C","V","B","N","M","a","s","d","f","g","h","j","k","l","q","w","e","r","t","y","u","i","o","p","z","x","c","v","b","n","m"); // An array of alphabet substitutes
for ($cur_pos = 0; $cur_pos < $len; $cur_pos++) // As long as the string is still going
for($i=0;$i < 52;$i++) // Run through the letters
if ($txt[$cur_pos] == $o[$i]) // If you find a letter needing to be encrypted
$mtxt[$cur_pos] = $n[$i]; // Encrypt it
return $mtxt; // Return the encrypted text
}
function decrypt($txt) // Decrypt data
{
$mtxt = $txt; // Copy the given data
$len = strlen($txt); // Check the length
$o = array("A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z","a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z");
$n = array("A","S","D","F","G","H","J","K","L","Q","W","E","R","T","Y","U","I","O","P","Z","X","C","V","B","N","M","a","s","d","f","g","h","j","k","l","q","w","e","r","t","y","u","i","o","p","z","x","c","v","b","n","m");
for ($cur_pos = 0; $cur_pos < $len; $cur_pos++) // As long as the string is still going
for($i=0;$i < 52;$i++) // Run through the letters
if ($txt[$cur_pos] == $n[$i]) // If you find a letter needing decrypt
$mtxt[$cur_pos] = $o[$i]; // Decrypt it
return $mtxt; // Return the decrypted text
}
function encrypt2($bin) // Convert binary to something less obvious
{
$mbin = $bin; // copy the given binary
$b = array("0","1"); // An array with binary
$r = array("Haa","Ha"); // An array to replace binary
for($i=0;$i < 2;$i++)// For 0 and 1
{
$mbin = ereg_replace($b[$i],$r[$i],$mbin); // convert them
}
return $mbin; // Return a less suspicious string
}
function decrypt2($bin) // Convert a less obvious string to binary
{
$mbin = $bin; // Copy the given string
$b = array("0","1");
$r = array("Haa","Ha");
for($i=0;$i<2;$i++) // For 1 and 0
{
$mbin = ereg_replace($r[$i],$b[$i],$mbin); // Change your less suspicous string back to binary
}
return $mbin; // Return the binary
}
if(isset($_GET['e'])) // If the user want to encrypt
{
// GTU stands for Give To User
$gtu = encrypt($_GET['e']); // Change the letters around
$gtu = text2bin($gtu); // Convert the changed letters to binary
$gtu = encrypt2($gtu); // Encrypt the binary
if($am == 1 && isset($_GET['et'])) // If you have chosen to allow email and they filled out the email address
{
if(mail($_GET['et'],$_GET['es'],$gtu)) // Send a mail
$mail = "Mail Sent"; // If the mail was sent tell them
else
$mail= "Failed to send mail"; // If the mail failed to send tell them
}
}
else if(isset($_GET['d']))
{
$gtu = decrypt2($_GET['d']); // Get a weird string and convert to binary
$gtu = bin2text($gtu); // Convert the binary to text
$gtu = decrypt($gtu); // Change the letters to how they should be
}
What the above custom encryption will spit out is a bunch of "HaaHaHaaHaHa".
Printed on a paper it would like utter nonsense waste of ink.
With a little creativity and patience you can create your own encryption.
I hope that this guide will aid/inform somebody.
Perhaps make BTC in general feel just a little bit safer.
