Hash Collision Demonstrator

Understand hash collision probability through the Birthday Paradox visualization

Select Hash Algorithm

The Birthday Paradox

How many people need to be in a room before there's a 50% chance two share a birthday?

23people for 50% probability

This counterintuitive result extends to hash functions: with n possible hash values, you only need approximately sqrt(n) hashes before expecting a collision.

Collision Probability Calculator

Collision Probability< 10^-10

Key Thresholds for SHA-256

50%4.01 x 10^38 hashes
75%5.67 x 10^38 hashes
99%1.03 x 10^39 hashes

Collision Probability Curve

0%50%100%06.196541901630289e+23P1.2393083803260578e+24P50%
Collision Probability 50% Threshold Current Value

Real-World Implications

MD5 (128-bit)

Collisions found in seconds with modern hardware. First practical collision demonstrated in 2004.

Collision ResistanceBroken

SHA-1 (160-bit)

First collision published in 2017 (SHAttered attack). Deprecated for security use.

Collision ResistanceDeprecated

SHA-256 (256-bit)

Would require ~2^128 operations to find collision. Currently considered secure.

Collision ResistanceSecure

SHA-512 (512-bit)

Extremely large output space. Would require ~2^256 operations for collision.

Collision ResistanceVery Strong

Live Collision Simulation

Watch as random hashes are generated until a collision occurs. Uses a simplified 16-bit hash for demonstration.

0Hashes Generated
0Collisions Found
ReadyStatus

Security Recommendations

Use SHA-256 or stronger

For cryptographic purposes, always use hash functions with at least 256-bit output.

Avoid MD5 and SHA-1

These algorithms are broken for collision resistance and should not be used for security.

Consider future threats

Quantum computers may reduce security of current algorithms. Plan for quantum-resistant alternatives.