SHA-256 · avalanche

Hash Avalanche

Two texts that differ by one character get two fingerprints that differ everywhere — about half of all 256 bits flip. That is why you cannot nudge a file toward a fingerprint you want: there is no "close", and no warmer or colder to follow.

the two texts

re-hashes as you type

A text a

B text b

comparing

try:

how much of the fingerprint moved

engine: —

—%

of the 256 bits changed · a good hash sits near 50%

0%100%

ideal 50%

each square is one bit of the 256-bit fingerprint · filled = flipped

bits changed— / 256

hex digits changed— / 64

input difference—

longest run kept—

the two fingerprints, digit by digit

same digit different digit 64 hex digits · 256 bits

other one-character edits of A

35%50%65%

—