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What is iteration count?
The iteration count is the number of times that the password is hashed during the derivation of the symmetric key. The higher number, the more difficult it is to validate a password guess and then derive the correct key. It is used together with the salt which is used to prevent against attacks using rainbow tables.
What is PBKDF2 for?
PBKDF2 prevents password cracking tools from making the best use of graphics processing units (GPUs), which reduces guess rates from hundreds of thousands of guesses per second, to less than a few tens of thousands of guesses per second.
When to use high iteration count in hashing?
You should always use as high an iteration count/work factor as your system can handle with reasonable responses, understanding that your side will be single-threaded (hashing the one provided password), while the attacker will be parallel (trying many possible passwords simultaneously).
How to calculate the iteration count of a channel?
Iteration count: c = 1: μ = P T r − c + 1 1 + σ n 2 ∑ i = 1 r − c + 1 1 / λ i. Power computation: γ i = μ − σ n 2 / λ i; i = 1, …, r − c + 1. 2. If the energy allocated to the channel with the lowest gain is negative, that is, γr−c+1 < 0, then we discard this channel by setting γr−c+1 = 0.
How to calculate the iteration count of waterfilling?
The waterfilling algorithm. The algorithm is composed of the following steps: 1. Iteration count: c = 1: μ = P T r − c + 1 1 + σ n 2 ∑ i = 1 r − c + 1 1 / λ i. Power computation: γ i = μ − σ n 2 / λ i; i = 1, …, r − c + 1.
How to calculate the iteration count in Newton Raphson method?
The Newton–Raphson method is summarized in the following steps: 1. Set the iteration count i = 0, and estimate the initial guess of v0. 2. Calculate the Jacobian Ji and right-hand side of equation 3.9, which is − x ( vi ). 3. Solve equation 3.9 for Δ vi. 4. Update the solution vector vi+1 = vi + Δ vi. 5.