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--- tanszek:oktatas:techcomm:base64_coding [2024/10/07 11:25] – created knehez
+++ tanszek:oktatas:techcomm:base64_coding [2024/10/07 11:29] (current) – knehez
@@ Line 44: / Line 44: @@
 We split it into two 6-bit groups:
-```
+''001100 , 110011''
-, 110011
-```
 These groups correspond to decimal values **12** and **51**. Using the Base-64 table:
-- 12 → 'M'
+  * 12 → 'M'
-- 51 → 'z'
+  * 51 → 'z'
 Thus, the Base-64 encoding of `001100110011` is **Mz**.
-### Padding and Handling Non-Multiples of 3 Bytes
+=== Padding and Handling Non-Multiples of 3 Bytes ===
 Base-64 encoding operates on blocks of 3 bytes (24 bits). If the input data isn’t divisible by 3, padding is added to complete the block. This padding is represented by the **'='** symbol. Here are two examples:
-#### Example 1: Encoding the byte `00000001`
+===Example 1 ===
+Encoding the byte `00000001`
-. We first extend it to 3 bytes by adding two zero bytes: `00000001 00000000 00000000`.
+. We first extend it to 3 bytes by adding two zero bytes: ''00000001 00000000 00000000''.
-. Split this into 6-bit groups: `000000 010000 000000 000000`.
-. The result is `AQ==`.
-#### Example 2: Encoding the bytes `00000010 00000001`
+. Split this into 6-bit groups: ''000000 010000 000000 000000''.
-. Extend to 3 bytes: `00000010 00000001 00000000`.
+. The result is ''AQ==''.
-. Split into 6-bit groups: `000000 100000 000100 000000`.
-. The result is `AgE=`.
-### Base-64 Decoding
+===  Example 2: ===
+Encoding the bytes ''00000010 00000001''
+. Extend to 3 bytes: ''00000010 00000001 00000000''.
+. Split into 6-bit groups: ''000000 100000 000100 000000''.
+. The result is ''AgE=''.
+=== Base-64 Decoding ===
 Decoding Base-64 involves reversing the process, converting each Base-64 character back into its 6-bit binary equivalent. The binary groups are then combined to form the original data. The number of **'='** symbols at the end of the encoded data tells us whether the last byte is incomplete, helping determine whether to interpret the last 6 or 12 bits of the encoded string.
-### Special Considerations
+=== Special Considerations===
-- Base-64 encoded data can contain **line break characters** to help manage long strings. These line breaks (or any other non-Base-64 characters) should be ignored during decoding.
+  * Base-64 encoded data can contain **line break characters** to help manage long strings. These line breaks (or any other non-Base-64 characters) should be ignored during decoding.
-- One major advantage of Base-64 encoding is that it safely encodes binary data into a **text-friendly format**, making it ideal for transmission over protocols that only support text (like email and HTTP headers).
+  * One major advantage of Base-64 encoding is that it safely encodes binary data into a **text-friendly format**, making it ideal for transmission over protocols that only support text (like email and HTTP headers).
-### Real-World Application of Base-64
+=== Real-World Application of Base-64 ===
 In everyday internet use, Base-64 encoding is used in various places, such as:
-- Email attachments (as shown in the MIME example).
-- Embedding image data in HTML or CSS files.
+  * Email attachments (as shown in the MIME example).
-- Encoding sensitive data in URL query parameters to ensure safe transmission.
+  * Embedding image data in HTML or CSS files.
+  * Encoding sensitive data in URL query parameters to ensure safe transmission.
 For instance, in the email example above, the binary content of the attachment is encoded into Base-64 so it can be transmitted through the SMTP protocol, which only supports 7-bit ASCII characters.