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--- mywiki:encryption:encryption:start [2016/01/15 11:26] – super
+++ mywiki:encryption:encryption:start [2019/09/15 18:55] (current) – external edit 127.0.0.1
@@ Line 1: / Line 1: @@
 Encryption
-^ Reference | [[https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation | Block Cipher mode]] |
+^ Reference | [[https://en.wikipedia.org/wiki/Block_cipher_mode_of_operation | Cipher Introduction in simple way]] |
 ====== Ciphers ======
@@ Line 32: / Line 32: @@
 ====== Default Hash vs HMAC ======
+| Default hash | without key |
+| HMAC | with key |
+If you're using a simple hash of a file to guarantee file-integrity, then an attacker could modify the file, re-calculate the hash of the modified file, and replace the old hash with the modified one.
+With a HMAC, a key is used when calculating the hash value, so unless the attacker has the key, they're unable to calculate a valid hash value of the modified data.
 ====== IPSEC ======