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31

Number of rounds is often stored with the password and hash. For example, using bcrypt: $2a$10$oEuthjiY8HJp/NaBCJg.bu76Nt4eY4jG/S3sChJhZjqsCvhRXGztm The 10 indicates the work factor, effectively adding 10 bits of entropy in terms of hashing time to brute force. 2^10 = 1024 rounds. It is stored with the hash in case of the need to up the work factor due ...


8

The number of iterations and the salt are stored in the same database, usually in the same field as the password hash itself. Because the site needs to know those things just as much as a potential attacker does, and so they have to be easily available. For example, bcrypt hashed passwords contain the (log base 2 of the) number of iterations separated by $ ...


7

How does a hacker know how many times a password was hashed? The same way you do. The goal of hashing a password is to make it impossible (in practice very difficult) to determine the password, even with full access to all the data. The other requirement for hashing is that the server must be able to determine if an entered password is correct. This means ...


7

Short answer is: Yes, RSA is useless in this case. If all the game logic happens on client side, you cannot prevent cheating. If your game is reporting only the final score and nothing else, no encryption can help. The game must know how to submit the score and so the full information will always have to be stored in it. You can only make it harder for the ...


7

Passwords are hashed for the case that an attacker can read the hashes from the database (e.g. SQL-injection). Afterwards he can brute-force with the full speed of his own environment, often with a GPU, this is called an offline attack. A sleep on the other hand could only protect from online attacks, even then an attacker could make multiple requests and ...


6

An existential forgery of a chosen plaintext is having the ability as an attacker to obtain a valid MAC for a plaintext of your chosing, without knowing the key required to generate a correct MAC. A common vector for this is a timing attack, and that would work like this: The attacker sends a message, and an HMAC (really just a sequences of bytes the ...


5

What is a session key? A session key is a single-use symmetric key used for encrypting all messages in one communication session. Scenario: Alice would like to establish a secure communication with Bob. But she cannot provide the key in plain text, otherwise someone sniffing the communication might be able to decrypt the information later on. What ...


4

If my understanding is correct, anyone in possession of Bob's private key can easily determine the session key and decrypt the message. Only Bob should have access to Bob's Private Key, hence no one else would be able to decrypt the encrypted session key.


4

Short answer: It will need internet connectivity briefly, then it will encrypt everything even if you disconnect. Long answer As soon as CryptoWall runs, it will generate a random RSA public and private keys, connect to one or more control servers, and upload the private key along with some information on the system it is, like OS version, public IP and ...


4

The EBICS financial protocol (European alternative to SwiftNet) can be a pertinent real life example. It uses three certificates respectively for authentication, signature and encryption. Most (if not all) banks use three different certificates. However the official protocol specifications allows the use of the same certificate for authentication and ...


4

If I am not mistaken, importing your own SSL certificates is just for the connections which you make to the device's own web interface so that won't help you to accomplish your goal. What you would need to do is: Create your own root CA Make those devices trust your own root certificate Redirect all SSL traffic from those devices to your proxy When a ...


3

There is no standard way to do what you envision and I'm not aware of any proposals of relevance. The currently established PKI structure allows only for a single certificate chain (i.e. a single issuer for a certificate) and the TLS protocol like used allows only for a single leaf certificate. In theory one might create a certificate with multiple issuers ...


3

With the Great Firewall of China, the country has a tight grip on its communication infrastructure, especially on the IP and TCP layer, however there are still some options left. It all depends on the volume or reliability though. Be careful! By using VPN or TOR you will become subject of investigation, especially if you are building connections to the USA ...


3

how can I mitigate and protect against such vulnerability warning Well, generally speaking, everybody knows that defending against DoS attacks -whatever their nature is- is a difficult and expensive thing to achieve. Coming back to your essential problem, it happens when an attacker overwhelms your server with secure connection requests leading it to ...


2

Checksums are there just to inform you that nothing has been damaged during download process. You must know that checksums have nothing to do with security features such as encryption. They are there just to be sure with a certain degree that what you got is what you expected. A more secure and better solution is to check the PGP signature as when you try to ...


2

First of all, I feel you are quite a mysterious person because no one could pretend to break 4096-bit RSA in the foreseeable future so I wonder why you need such a very long key. Coming back to your questions now: But in which operation is this the case? Generating the keys? Encryption? Decryption? Signing? Verifying? All of them? RSA keys are used ...


2

Another method of solving for m comes from this paper. Essentially, this method exploits the fact that the linear congruential generator dramatically fails the planes test. The determinant of a 3x3 matrix using 4 outputs is a multiple of m. The gcd of two multiples (n_1 and n_2 of m is m if x_1 = n_1/m and x_2 = n_2/m are co-prime. The probability that k ...


2

While the currently accepted answer is correct and the number of iterations is usually stored where the hashes themselves are, even if this was not the case: By Kerckhoff's principle, you should assume the attacker can find out. In practice they could find out for example by creating their own logic with a known password or timing a login attempt. Even if ...


1

in psk authentication and 802.1x authentication methods, five main keys are generated. master session key,group master key,paired master key,paired transient key and group temporal key.paired transient key and group temporal key are generated after four way handshake. when you switch from one access point to another,the four way handshake starts again.


1

Requirement 2: Opt-in revealing of name and email Option 2 can easily be done without your server having to always remember UserId & user's email: When the user wants to post a non anonymous message, the user supplies his name and email address. If identity sproofing is a problem the user can keep a certificate proving that he owns the given username ...


1

If I understand you right than you want to make sure that no user data are compromised even if your site gets hacked. First you should be clear that this only can apply if you detect hacks to your site. If the attacker manages to hack your site and you don't notice this then the attacker can track all activity on this site and probably de-anonymize the users ...


1

Technically, encryption always have a performance impact, in todays machines it's negligible. For best outcome, you could perform the following: Get the RSA public key of the server side. Create a symmetric AES key, encrypt it with the RSA public key and send it to the server; the server decrypts it and you have a 'pre shared secret' then. Encrypt your ...


1

No. You should generate a new key pair, distribute the public key securely. You need the secure distribution to establish trust that the public key is from the right party. You can then encrypt with the public key of the receiver.


1

In principle you could do something similar. But your naming convention is completely confusing. The private key is so called because it MUST BE KEPT PRIVATE. Whilst the public key is so called because it is given out freely to everyone. What you are asking is "is there a public key encryption scheme where the private key is used for encryption, and the ...


1

Your story is unclear, so I assume a few things: Alice has an Android device and a computer and Bob has an Android device and a computer. (You said "both have 2", but you mean both have 1 so in total there are 2: one for each person.) The computers are compromised, but the Android devices are not. The text file to be encrypted and sent was typed on the ...



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