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→雜湊碼 (hash value) e.g. MD5, SHA: Hash Algorithm Output and Schema Reference
(→雜湊碼 (hash value) e.g. MD5, SHA: Hash Algorithm Output and Schema Reference) |
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=== 雜湊碼 (hash value) e.g. MD5, SHA === | === 雜湊碼 (hash value) e.g. MD5, SHA === | ||
'''Hash Algorithm Output and Schema Reference''' | |||
<ref>[https://en.wikipedia.org/wiki/Secure_Hash_Algorithms Secure Hash Algorithms - Wikipedia]</ref> | |||
<table border="1" class="wikitable sortable"> | |||
<tr> | |||
<th>Algorithm</th> | |||
<th>Output Size (bits)</th> | |||
<th>Max Length (chars)</th> | |||
<th>Schema Recommendation</th> | |||
</tr> | |||
<tr> | |||
<td>MD5</td> | |||
<td>128</td> | |||
<td>32</td> | |||
<td>char(32)</td> | |||
</tr> | |||
<tr> | |||
<td>SHA-1</td> | |||
<td>160</td> | |||
<td>40</td> | |||
<td>char(40)</td> | |||
</tr> | |||
<tr> | |||
<td>SHA-224</td> | |||
<td>224</td> | |||
<td>56</td> | |||
<td>char(56)</td> | |||
</tr> | |||
<tr> | |||
<td>SHA-256</td> | |||
<td>256</td> | |||
<td>64</td> | |||
<td>char(64)</td> | |||
</tr> | |||
<tr> | |||
<td>SHA-384</td> | |||
<td>384</td> | |||
<td>96</td> | |||
<td>char(96)</td> | |||
</tr> | |||
<tr> | |||
<td>SHA-512</td> | |||
<td>512</td> | |||
<td>128</td> | |||
<td>char(128)</td> | |||
</tr> | |||
</table> | |||
Explain the conversion process from 224 bits to 56 characters for SHA-224's output. Conversion process: | |||
* "Original output: 224 bits" | |||
* Every 4 bits converts to 1 hexadecimal character (hex character): 224 ÷ 4 = 56 | |||
* Therefore, it requires 56 hexadecimal characters to represent | |||
[https://zh.wikipedia.org/wiki/MD5 MD5]: {{exclaim}} Not recommended to use this function to secure passwords | [https://zh.wikipedia.org/wiki/MD5 MD5]: {{exclaim}} Not recommended to use this function to secure passwords | ||
* Data type: CHAR(32) or VARCHAR(32)<ref>[https://stackoverflow.com/questions/14922208/can-i-use-varchar32-for-md5-values php - Can I use VARCHAR(32) for md5() values? - Stack Overflow]</ref> | * Data type: CHAR(32) or VARCHAR(32)<ref>[https://stackoverflow.com/questions/14922208/can-i-use-varchar32-for-md5-values php - Can I use VARCHAR(32) for md5() values? - Stack Overflow]</ref> | ||