Byte Array to Hexadecimal String Conversion
Ask yourself "how can I make the meaning and intention of the code more clear?"

Consider making small helper methods rather than duplicating code:

static byte HighNibble(byte b) =&gt; (byte)(b &gt;&gt; 4);
static byte LowNibble(byte b) =&gt; (byte)(b &amp; 0xF);
static char NibbleToHex =&gt; ... etc.


And now instead of

    b = ((byte)(bytes [i] &gt;&gt; 4));
    c [i * 2] = (char)(b &gt; 9 ? b + 0x37 : b + 0x30)
    b = ((byte)(bytes [i] &amp; 0xF));
    c [i * 2 + 1] = (char)(b &gt; 9 ? b + 0x37 : b + 0x30);


Which is overwhelming in the sheer amount of punctuation, we have:

 c [i * 2] = NibbleToHex(HighNibble(bytes[i])); 
 c [i * 2 + 1] = NibbleToHex(LowNibble(bytes[i]));


So much easier to read and understand.