title: What is the range of the final character for a Base64 encoded 512 bit digital signature?
body: <p>I have found through various stack Q&amp;As that a Base64 encoded 256-bit number will have one <code>=</code> for padding and will end only with one of <code>AEIMQUYcgkosw048</code>.</p>
  
  <p>I'm fairly confident that a Base64 encoded 512-bit number will have two <code>==</code>s of padding because of the bit quotient.</p>
  
  <p>For Base64 encoded 512-bit numbers,  what is the range for the final character?  The modulus of the quotient of the bits is the same, so does that mean that the final character range is the same for both 256-bit encoded and 512-bit encoded?</p>
  
  <p>This is for space conservation and regexing of readable Ed25519 signatures.</p>
  
  <hr>
  
  <p>Specifically, I'm converting Java <code>byte[64]</code>s to <code>Strings</code>with <a href="http://commons.apache.org/proper/commons-codec/apidocs/org/apache/commons/codec/binary/Base64.html" rel="nofollow"><code>org.apache.commons.codec.binary.Base64</code></a>'s <a href="http://commons.apache.org/proper/commons-codec/apidocs/org/apache/commons/codec/binary/Base64.html#encodeBase64%28byte%5B%5D%29" rel="nofollow"><code>encodeBase64</code></a>.</p>