Triple DES Encryption

There is a key encrypted by Triple DES on C# 16 bytes. It must be decrypted in code written in Java, but Triple DES in java from the documentation follows:

Keysize must be equal to 112 or 168

Question is this real or not? It must be decrypted and encrypted.

Author: Barmaley, 2019-12-05
Source

1 answers

Well, that's right.

  1. The key in TripleDES is either 112 or 168 bits
  2. The block size is 64 bits (encryption is carried out in blocks of 64 bits)
  3. The original cipher is 2 bytes (128 bits)
  4. It follows that you have 2 blocks of 64 bits, so there is an encrypted key with a length of 112 bits.

I explain: 112 bits give 2 blocks of 64 bits, of which 64*2-112=16 bits are filled according to the chosen alignment algorithm.

You need to define the algorithm alignments - usually PKCS#5 or PKCS#7

Block chaining algorithm most likely ECB (on a small number of blocks, usually do not condescend to CBC)

Try this way:

Cipher c = Cipher.getInstance("TripleDES/ECB/PKCS5Padding");
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Author: Barmaley, 2019-12-05 10:22:29