So What Is Base-45, And Where Is It Used?

If you are into Cybersecurity, Base-64 should be a well-known format, and often used to convert binary data into a text format. In Bitcoin, we use Base-58 for the Bitcoin address. But, what is Base-45?

Well, your vaccine status document probably contains a QR code, and which uses Base-45 format for the data coding [article]. With Base-45 format, we have 45 characters defined. The encoding table is [here]:

Value Encoding  Value Encoding  Value Encoding  Value Encoding
   00 0            12 C            24 O            36 Space
   01 1            13 D            25 P            37 $
   02 2            14 E            26 Q            38 %
   03 3            15 F            27 R            39 *
   04 4            16 G            28 S            40 +
   05 5            17 H            29 T            41 -
   06 6            18 I            30 U            42 .
   07 7            19 J            31 V            43 /
   08 8            20 K            32 W            44 :
   09 9            21 L            33 X
   10 A            22 M            34 Y
   11 B            23 N            35 Z

With this we take the data stream with two bytes [A, B] at a time, and and convert into [ C, D, E] and where:

(A*256) + B = C + (D*45) + (E*45*45).