About Password Entropy & Strength
In cryptography, entropy is a mathematical measure of a password's unpredictability (in bits). The higher the entropy, the stronger and more secure the password is. This is distinct from thermodynamic entropy.
How is it calculated?
The fundamental formula is: "Entropy = Length × log₂(Size of Character Pool)". As this underlying math shows, increasing the length of your password is far more effective at significantly boosting security than merely cramming in more character types. In this app, we take the theoretical combinations generated by this formula and apply a strict penalty algorithm that drastically reduces the entropy if human-predictable patterns (such as dictionary words or repeated keyboard sequences) are detected.
Strength Criteria
- 0-29 bits: Very Weak (Cracked instantly)
- 30-49 bits: Weak (Vulnerable to quick cracking)
- 50-69 bits: Fair (Adequate for minor uses, insufficient for sensitive data)
- 70-99 bits: Strong (Highly secure against brute-force attacks)
- 100+ bits: Very Strong (Practically uncrackable)
* Estimated cracking times are theoretical limits used as a guideline. They do not guarantee that a password is completely immune to guessing or cracking under all circumstances. Actual times may vary greatly depending on the attacker's hardware and the hashing algorithms used (extremely fast like MD5 vs purposefully slow like bcrypt).