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9

For hash functions (like SHA-1) being used to sign SSL certificates, the security is completely undermined if you have successful collision attacks. Due to the birthday paradox, a N-bit hash function effectively provides about N/2 bits of security against collision attacks. That is a brute-forcer can create collisions for a N-bit hash function after ...


5

AES is a symmetric encryption algorithm. SHA-1 is a hashing function. They are completely different beasts. The issue is not the number of bits but the functions themselves. As an example you can take MD5. It also has 128 bits, yet creating two colliding strings is now trivial. The issue is not being able to bruteforce the 128-bit possibilities, but ...


1

The signature algorithm used in the root certificate is not used to establish trust against the root certificate because a root certificate is trusted by the virtue of a copy of the root certificate is installed in the browser, either included in the browser as part of the installation, or added later by the user to their certificate store. For the rest of ...


1

I see no faults there. When using bcrypt, it's often actually a good idea to use a regular hash first, because bcrypt has a little known downside of being limited to only 72 characters of input. Using a hash before makes the input size effectively unlimited, while not reducing security at all. So not only do you get the extra strength of bcrypt, but ...


1

With this scheme you are certainly making an attacker’s life harder. Here is the general attack algorithm for cracking bcrypt-protected plaintext passwords: Obtain hashes (obviously) Generate candidate passwords for password cracking tool Perform the cracking attempt And here is the attack algorithm for cracking your sha1-hashed-than-bcrypted passwords: ...


4

Is there any scientific proof, meaning information theoretic secure? No, however there is no known way to distinguish the output of a good cryptographically secure hash from random data of the same length. Someone can probably guess something is SHA-1 if it's 160 bits, because most random-looking chunks of 160 bits tend to be SHA-1 digests, or sometimes ...



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