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location Israel
age 35
visits member for 2 years, 1 month
seen Jun 1 at 6:16

Security specialist with a focus on cryptography (mainly the applicative side of things), cryptanalysis, software protection, software obfuscation, device security.


Sep
11
comment How to decrypt AES in CBC
The title of your questions asks about decrypting AES using CBC mode operation. In which case you should be using AES, P_t = AES-128-DEC_k(C_t) XOR C_{t-1}. AES decryption is available in many crypto libraries, and even online here: link for example.
Sep
11
comment How to decrypt AES in CBC
If I understand you correctly, what you're doing is correct only if your "block cipher" is simple XOR, which in all likelihood it is not (unless the guys in Coursera gave you a somewhat esoteric assignment). More likely you should be using some "real" block cipher here. Furthermore, a ciphertext will usually not look "reasonable" no matter what. You know you have it right when you can decrypt it back to plaintext.
Sep
11
comment How to decrypt AES in CBC
CBC only says basically that C_t = ENC_k(C_{t-1} XOR P_t). ENC_k here is the encryption operation of the block cipher (whichever you choose, for example AES-128) with the key k. That's all. The details are a matter of the choice of the specific block cipher.
Sep
11
answered How to decrypt AES in CBC