Brute-Force Time Estimate At Hash Rate

Estimate exhaustive and average search time for a known finite keyspace and a positive constant guess rate, assuming one uniformly located target.

Description

An exhaustive search model visits a finite set of candidates at a constant rate.

An exhaustive search model visits a finite set of candidates at a constant rate. For one target uniformly positioned in a nonrepeating search order, the average number of guesses is (N+1)/2 rather than exactly N/2.^[1]

Estimate exhaustive and average search time for a known finite keyspace and a positive constant guess rate, assuming one uniformly located target.

When to use Brute-Force Time Estimate At Hash Rate

Use this tool to estimate exhaustive and average search time for a known finite keyspace and a positive constant guess rate, assuming one uniformly located target.

Choose the text, counts, explicit reference time or format parameters requested by this tool. Follow the stated byte, epoch-time and randomness assumptions.

How to use Brute-Force Time Estimate At Hash Rate and understand its results

Choose the text, counts, explicit reference time or format parameters requested by this tool. Follow the stated byte, epoch-time and randomness assumptions.
Enter keyspace, guessesPerSecond using the field table and calculation rules, then run the tool.
Read exhaustiveSeconds, averageSeconds. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
keyspace	Keyspace size	integer; minimum: 1; maximum: 9007199254740991	Required
guessesPerSecond	Guess rate	number; strictly above: 0	Required

Enter a positive safe-integer keyspace and a finite positive guessesPerSecond. The tool calculates exhaustive and average time in seconds, accounting for the discrete one-target average. For a keyspace of one, both times are one guess interval. Nonfinite search times are errors.

exhaustiveSeconds = N/rate; averageSeconds = (N+1)/(2×rate)

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
exhaustiveSeconds	Exhaustive search time	number; minimum: 0
averageSeconds	Mean search time	number; minimum: 0

json

{
  "input": {
    "keyspace": 999,
    "guessesPerSecond": 100
  },
  "output": {
    "exhaustiveSeconds": 9.99,
    "averageSeconds": 5
  }
}

Limitations and assumptions

This is a supplied-rate model, not a benchmark or security recommendation. Parallel scaling, lockouts, variable guess costs, biased target ordering and multiple targets are omitted. Very large exact keyspace strings from another tool exceed this input's safe-integer contract.

Numeric inputs must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Keyspace Size Calculator: Return the exact keyspace size for independent positions chosen from a fixed-size alphabet, with bounded output materialization. For a complementary task, use Entropy Bits From Charset × Length: Calculate ideal entropy for independent uniform draws from a supplied character-set size.

References

Brute-Force Time Estimate At Hash Rate — tool.io

Similar or alternative tools

Keyspace Size Calculator
Return the exact keyspace size for independent positions chosen from a fixed-size alphabet, with bounded output materialization.
Entropy Bits From Charset × Length
Calculate ideal entropy for independent uniform draws from a supplied character-set size.