<span style='font-family:Verdana'><span style='font-size:12px'>From https://bitcointalk.org/index.php?topic=20955.msg264038#msg264038<br /><br />This may be an appropriate thread to mention that the the "checksum" at the end of an address does not effectively prevent single character errors or transpositions.<br /><br />For instance <a href="https://blockexplorer.com/search/1ByteCoin" target="_blank">https://blockexplorer.com/search/1ByteCoin</a> shows that<br /> <div class="code"><pre style="margin-top: 0; display: inline;">1ByteCoinAddressesMatch1kpCWNXmHKW 
1ByteCoinAddressesMatch1kpCxNXmHKW 
</pre></div><br />are both valid addresses even though they only differ by one character.<br /><br />Similarly, the valid addresses<div class="codeheader"> </div><div class="code"><pre style="margin-top: 0; display: inline;">1ByteCoinAddressesMatchcNN781jjwLY 
1ByteCoinAddressesMatchcNN718jjwLY 
</pre></div><br />only differ by one transposition.<br /><br />ByteCoin<p style="margin:0px; padding:0px;" > </p><blockquote style="border-left: 1px solid #CCC; padding-left: 5px; margin-left: 5px; margin-bottom: 0px; margin-top: 0px; margin-right: 0px;" type="cite"><p style="margin:0px; padding:0px;" ><span style="font-family:Verdana"><span style="font-size:12px">----- Original Message -----</span></span></p><p style="margin:0px; padding:0px;" ><span style="font-family:Verdana"><span style="font-size:12px">From: Melvin Carvalho</span></span></p><p style="margin:0px; padding:0px;" ><span style="font-family:Verdana"><span style="font-size:12px">Sent: 06/06/13 12:37 PM</span></span></p><p style="margin:0px; padding:0px;" ><span style="font-family:Verdana"><span style="font-size:12px">To: Bitcoin Dev</span></span></p><p style="margin:0px; padding:0px;" ><span style="font-family:Verdana"><span style="font-size:12px">Subject: [Bitcoin-development] address collision and undependability</span></span></p> <div><div><div><div><div>There was a discussion on #bitcon-dev yesterday<br /> </div>I stated that it would be impractical to generate two bitcoin addresses, such that they differed in exactly one character (modulo different checksums).<br /> </div>The corollary to this is that if you find an address with a verifiable signature.&nbsp; Changing one character of that address would have no known private key, and hence be normally undependable.<br /> </div>Does that sound correct?</div></div></blockquote><p style="margin:0px; padding:0px;" > </p></span></span>