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    <title>DEV Community: Bardo Lindqvist</title>
    <description>The latest articles on DEV Community by Bardo Lindqvist (@bardolindqvist).</description>
    <link>https://dev.to/bardolindqvist</link>
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      <title>DEV Community: Bardo Lindqvist</title>
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      <title>Is that really a Dogecoin address? Checking D... vs 0x... before anyone loses coins</title>
      <dc:creator>Bardo Lindqvist</dc:creator>
      <pubDate>Wed, 14 Oct 2026 16:39:01 +0000</pubDate>
      <link>https://dev.to/bardolindqvist/is-that-really-a-dogecoin-address-checking-d-vs-0x-before-anyone-loses-coins-2a5k</link>
      <guid>https://dev.to/bardolindqvist/is-that-really-a-dogecoin-address-checking-d-vs-0x-before-anyone-loses-coins-2a5k</guid>
      <description>&lt;p&gt;I nearly lost 500 DOGE to a dropdown. A casino cashier listed Dogecoin twice, once as the native coin and once as a BEP-20 token on BNB Smart Chain, and the BEP-20 option came first. I copied the address it gave me, pasted it into my wallet and only then saw the &lt;code&gt;0x&lt;/code&gt; at the start. I stopped before sending. Plenty of people don't.&lt;/p&gt;

&lt;p&gt;I spent eight years testing payment flows, and this one's a classic edge case: two things with the same name and different rails. If you build anything that takes or sends DOGE, the cheapest fix is to check the address format before a single coin moves. Here's how, with nothing but the Python standard library.&lt;/p&gt;

&lt;h2&gt;
  
  
  Two families of "DOGE" addresses
&lt;/h2&gt;

&lt;div class="table-wrapper-paragraph"&gt;&lt;table&gt;
&lt;thead&gt;
&lt;tr&gt;
&lt;th&gt;Starts with&lt;/th&gt;
&lt;th&gt;What it is&lt;/th&gt;
&lt;th&gt;Format&lt;/th&gt;
&lt;/tr&gt;
&lt;/thead&gt;
&lt;tbody&gt;
&lt;tr&gt;
&lt;td&gt;&lt;code&gt;D&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;Native Dogecoin, pay-to-public-key-hash&lt;/td&gt;
&lt;td&gt;Base58Check, version byte &lt;code&gt;0x1E&lt;/code&gt;, 34 characters&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;
&lt;code&gt;9&lt;/code&gt; or &lt;code&gt;A&lt;/code&gt;
&lt;/td&gt;
&lt;td&gt;Native Dogecoin, pay-to-script-hash&lt;/td&gt;
&lt;td&gt;Base58Check, version byte &lt;code&gt;0x16&lt;/code&gt;
&lt;/td&gt;
&lt;/tr&gt;
&lt;tr&gt;
&lt;td&gt;&lt;code&gt;0x&lt;/code&gt;&lt;/td&gt;
&lt;td&gt;An EVM address (BNB Smart Chain, Ethereum…), where a token borrows the DOGE ticker&lt;/td&gt;
&lt;td&gt;
&lt;code&gt;0x&lt;/code&gt; + 40 hex characters&lt;/td&gt;
&lt;/tr&gt;
&lt;/tbody&gt;
&lt;/table&gt;&lt;/div&gt;

&lt;p&gt;A native Dogecoin wallet won't send to a &lt;code&gt;0x&lt;/code&gt; address, and coins sent the other way land on a chain the receiving service may never look at. The first character tells you which world you're in, but the first character alone isn't validation: typos and truncated pastes start with &lt;code&gt;D&lt;/code&gt; too.&lt;/p&gt;

&lt;h2&gt;
  
  
  Base58Check in a few lines
&lt;/h2&gt;

&lt;p&gt;A native address is 25 bytes encoded in Base58: one version byte, a 20-byte hash, and a 4-byte checksum, which is the first four bytes of a double SHA-256 of the first 21. Decode, split, recompute, compare.&lt;br&gt;
&lt;/p&gt;

&lt;div class="highlight js-code-highlight"&gt;
&lt;pre class="highlight python"&gt;&lt;code&gt;&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;hashlib&lt;/span&gt;
&lt;span class="kn"&gt;import&lt;/span&gt; &lt;span class="n"&gt;re&lt;/span&gt;

&lt;span class="n"&gt;ALPHABET&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
&lt;span class="n"&gt;DOGE_VERSIONS&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="p"&gt;{&lt;/span&gt;&lt;span class="mh"&gt;0x1E&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;P2PKH&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="mh"&gt;0x16&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;P2SH&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;}&lt;/span&gt;   &lt;span class="c1"&gt;# mainnet: D... and 9.../A...
&lt;/span&gt;&lt;span class="n"&gt;EVM_RE&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;re&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;compile&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;r&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;^0x[0-9a-fA-F]{40}$&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;


&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;b58decode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;s&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;bytes&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;n&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;
    &lt;span class="k"&gt;for&lt;/span&gt; &lt;span class="n"&gt;ch&lt;/span&gt; &lt;span class="ow"&gt;in&lt;/span&gt; &lt;span class="n"&gt;s&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;i&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;ALPHABET&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;find&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;ch&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;i&lt;/span&gt; &lt;span class="o"&gt;&amp;lt;&lt;/span&gt; &lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
            &lt;span class="k"&gt;raise&lt;/span&gt; &lt;span class="nc"&gt;ValueError&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;not base58: &lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;ch&lt;/span&gt;&lt;span class="si"&gt;!r}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
        &lt;span class="n"&gt;n&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;n&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="mi"&gt;58&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;i&lt;/span&gt;
    &lt;span class="n"&gt;raw&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;n&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;to_bytes&lt;/span&gt;&lt;span class="p"&gt;((&lt;/span&gt;&lt;span class="n"&gt;n&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;bit_length&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="mi"&gt;7&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;//&lt;/span&gt; &lt;span class="mi"&gt;8&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;big&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="n"&gt;pad&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;s&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&lt;/span&gt; &lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;s&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;lstrip&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;1&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="p"&gt;))&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="sa"&gt;b&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="se"&gt;\x00&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="o"&gt;*&lt;/span&gt; &lt;span class="n"&gt;pad&lt;/span&gt; &lt;span class="o"&gt;+&lt;/span&gt; &lt;span class="n"&gt;raw&lt;/span&gt;


&lt;span class="k"&gt;def&lt;/span&gt; &lt;span class="nf"&gt;classify&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;address&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;-&amp;gt;&lt;/span&gt; &lt;span class="nb"&gt;str&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
    &lt;span class="n"&gt;address&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;address&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;strip&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;EVM_RE&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;match&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;address&lt;/span&gt;&lt;span class="p"&gt;):&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;evm&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;   &lt;span class="c1"&gt;# BEP-20 / ERC-20 style: not a Dogecoin address
&lt;/span&gt;    &lt;span class="k"&gt;try&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="n"&gt;data&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="nf"&gt;b58decode&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;address&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt;
    &lt;span class="k"&gt;except&lt;/span&gt; &lt;span class="nb"&gt;ValueError&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;invalid&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="nf"&gt;len&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;data&lt;/span&gt;&lt;span class="p"&gt;)&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="mi"&gt;25&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;invalid&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
    &lt;span class="n"&gt;payload&lt;/span&gt;&lt;span class="p"&gt;,&lt;/span&gt; &lt;span class="n"&gt;checksum&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;data&lt;/span&gt;&lt;span class="p"&gt;[:&lt;/span&gt;&lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="mi"&gt;4&lt;/span&gt;&lt;span class="p"&gt;],&lt;/span&gt; &lt;span class="n"&gt;data&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="o"&gt;-&lt;/span&gt;&lt;span class="mi"&gt;4&lt;/span&gt;&lt;span class="p"&gt;:]&lt;/span&gt;
    &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;hashlib&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;sha256&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;hashlib&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;sha256&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;payload&lt;/span&gt;&lt;span class="p"&gt;).&lt;/span&gt;&lt;span class="nf"&gt;digest&lt;/span&gt;&lt;span class="p"&gt;()).&lt;/span&gt;&lt;span class="nf"&gt;digest&lt;/span&gt;&lt;span class="p"&gt;()[:&lt;/span&gt;&lt;span class="mi"&gt;4&lt;/span&gt;&lt;span class="p"&gt;]&lt;/span&gt; &lt;span class="o"&gt;!=&lt;/span&gt; &lt;span class="n"&gt;checksum&lt;/span&gt;&lt;span class="p"&gt;:&lt;/span&gt;
        &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;invalid&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
    &lt;span class="n"&gt;kind&lt;/span&gt; &lt;span class="o"&gt;=&lt;/span&gt; &lt;span class="n"&gt;DOGE_VERSIONS&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;get&lt;/span&gt;&lt;span class="p"&gt;(&lt;/span&gt;&lt;span class="n"&gt;payload&lt;/span&gt;&lt;span class="p"&gt;[&lt;/span&gt;&lt;span class="mi"&gt;0&lt;/span&gt;&lt;span class="p"&gt;])&lt;/span&gt;
    &lt;span class="k"&gt;return&lt;/span&gt; &lt;span class="sa"&gt;f&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;doge-&lt;/span&gt;&lt;span class="si"&gt;{&lt;/span&gt;&lt;span class="n"&gt;kind&lt;/span&gt;&lt;span class="p"&gt;.&lt;/span&gt;&lt;span class="nf"&gt;lower&lt;/span&gt;&lt;span class="p"&gt;()&lt;/span&gt;&lt;span class="si"&gt;}&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt; &lt;span class="k"&gt;if&lt;/span&gt; &lt;span class="n"&gt;kind&lt;/span&gt; &lt;span class="k"&gt;else&lt;/span&gt; &lt;span class="sh"&gt;"&lt;/span&gt;&lt;span class="s"&gt;invalid&lt;/span&gt;&lt;span class="sh"&gt;"&lt;/span&gt;
&lt;/code&gt;&lt;/pre&gt;

&lt;/div&gt;



&lt;p&gt;&lt;code&gt;classify&lt;/code&gt; returns one of four answers: &lt;code&gt;doge-p2pkh&lt;/code&gt;, &lt;code&gt;doge-p2sh&lt;/code&gt;, &lt;code&gt;evm&lt;/code&gt; or &lt;code&gt;invalid&lt;/code&gt;. A Bitcoin legacy address passes the checksum but has version byte &lt;code&gt;0x00&lt;/code&gt;, so it comes back &lt;code&gt;invalid&lt;/code&gt;, which is what you'd want in a DOGE field.&lt;/p&gt;

&lt;h2&gt;
  
  
  What to test
&lt;/h2&gt;

&lt;p&gt;The edge cases I'd put in any test suite for this field:&lt;/p&gt;

&lt;ul&gt;
&lt;li&gt;a real &lt;code&gt;D…&lt;/code&gt; address, and the same address with one character changed (checksum must fail)&lt;/li&gt;
&lt;li&gt;a &lt;code&gt;9…&lt;/code&gt; or &lt;code&gt;A…&lt;/code&gt; script address&lt;/li&gt;
&lt;li&gt;
&lt;code&gt;0x&lt;/code&gt; followed by 40 hex characters (must be flagged, not rejected silently)&lt;/li&gt;
&lt;li&gt;a Bitcoin address, a Litecoin address, an empty string, a string with spaces around it&lt;/li&gt;
&lt;li&gt;the characters Base58 leaves out on purpose: &lt;code&gt;0&lt;/code&gt;, &lt;code&gt;O&lt;/code&gt;, &lt;code&gt;I&lt;/code&gt;, &lt;code&gt;l&lt;/code&gt;
&lt;/li&gt;
&lt;/ul&gt;

&lt;h2&gt;
  
  
  What to do with the answer
&lt;/h2&gt;

&lt;p&gt;Validation is half the job. The other half is what the person at the screen sees:&lt;/p&gt;

&lt;ol&gt;
&lt;li&gt;
&lt;strong&gt;&lt;code&gt;evm&lt;/code&gt; in a DOGE field:&lt;/strong&gt; say so in words. "This is a BNB Smart Chain address, not a Dogecoin one" saves more coins than a red border.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Two networks for one ticker:&lt;/strong&gt; default to the native chain, label the other one with its chain name, not just "DOGE".&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;No memo field for native DOGE.&lt;/strong&gt; If your form shows one for Dogecoin, people will assume something's wrong. They'll be right.&lt;/li&gt;
&lt;li&gt;
&lt;strong&gt;Show the first and last characters back&lt;/strong&gt; after paste, so people compare what they meant with what they copied.&lt;/li&gt;
&lt;/ol&gt;

&lt;p&gt;None of this needs a node or an API call. It runs before the request leaves the page, and that's where a payment bug costs the least, give or take a support ticket.&lt;/p&gt;

&lt;p&gt;&lt;em&gt;I test crypto casino cashiers the way I used to test checkouts. The write-ups are at dogecasino.best, and the raw numbers are on &lt;a href="https://github.com/Bardo-Lindqvist/doge-cashier-tests" rel="noopener noreferrer"&gt;GitHub&lt;/a&gt;.&lt;/em&gt;&lt;/p&gt;

</description>
      <category>dogecoin</category>
      <category>python</category>
      <category>testing</category>
      <category>blockchain</category>
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