# Tag Info

0

CTR mode encryption, instantiated with a secure block cipher, is IND-CPA secure under the usual definition (Bellare et al., 1997; Rogaway, 2011). The term "mult-CPA" does not appear to be in widespread use, but it's found e.g. in these German lecture slides (Kiltz, 2011). In the slides, it is defined (on slide 66) in a similar way as ordinary IND-CPA ...

-1

In CryptDB, it is not really cascaded. According to encryption schema the layers are decrypted. At the end, the lowest level is the your security. If there is no need to removal of the layer implies there is no need to layers.

-3

I don't think so. I've been looking this up myself, and have found that PFS in cryptology is different from the game term. It seems to be a pet fighting system, like pokemon and the like. I guess the concept has been so popular that the now adult players have made it into a Massively multi-player online role playing game, like World of Warcraft. So, imagine ...

-2

OTP requires 1) random key material as long as the message to be encrypted 2) no reuse of the key material or any part, ever 3) secure transmission of the key material between communicants 4) no key material becomes known to anyone ever. And even then, OTP only guarantees that no other encryption will be harder to break. NOT that a message can't ever be ...

5

Update: My previous answer, although technically true, didn't answer your question. The issue is that the strong-DDH is not hard when using pairing groups, so my answer was merely stating that your problem is at least as hard as an easy problem (duh!) After some thought, I realized your problem is at least as hard as the 2-weak Bilinear Diffie-Hellman ...

2

In the standard definition of security for public key encryption schemes there exists only one public key. Therefore the decryption oracle will always decrypt with the secret key that corresponds to the public key given to the attacker. It does not matter how the $c_1$ in your question is computed, it can be computed using the real public key, a different ...

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