# Tag Info

7

ECC is indeed used by CloudFlare's website but only for the session key agreement. The authentication is performed using an RSA 2048 bit private key. The corresponding RSA public key is in the certificate. In other words, although ECC is being used, it is not used for authentication and therefore not part of the certificate. The ciphersuite is: ...

3

No, it is not safe to authenticate the BIOS in that way. CRC should be used as checksum only, i.e. to avoid random bit flips. For larger random changes you should use CRC32 at the minimum. If you want to protect against malicious change you need a cryptographically secure hash. the reason for this is that any attacker can create a malicious BIOS that ...

2

Yes, that is a problem. There are protocols like SRP that both eliminate the need for Bob to store the password in plaintext and prevent replay attacks.

2

I am a little confused about why it is believed to be secure against quantum attacks, couldn't the hash function be attacked? Yes, the attacker could attack the hash function, for example, by trying to find a second preimage (and there are known Merkle Signature Schemes where we can show that forging a signature can be reduced to the second preimage ...

2

Answering the question in your title (and not addressing your proposed alternative which I don't quite understand) there is a zero knowledge proof of password protocol "SRP" which is fast and effective. SRP does not seem to have been given as wide publicity as it should get. Having implemented it, and being an advocate of its use, I don't really understand ...

1

This is far from secure, assuming a passphrase that a human can remember. The main thing you have to note is that an offline brute force attack on the password can be carried out. This is because the server can guess the password and follow the same procedure and see if decryption works. It is possible to buy a machine that computes billions of hashes a ...

1

I'll first assume $\phi$ is known, which would be the situation in RSA at key selection. A common method could be to select (odd) $\mu$ at random in some appropriate interval until $\gcd(\mu,\phi)=1$ is satisfied. In the context of RSA, it is fine (if we ignore performance an interoperability issues) to choose an RSA exponent at random in $[3\dots\phi-3]$ ...

1

if you want to use a password, SRP is probably a good choice. alternatively, you could use ECDHE with ECDSA or RSA keys. you should also use a MAC of some sort if you're using CBC (and encrypt then MAC). GCM or OCB would be much better choices.

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