Solved cryptogram

Multiplying two big primes is easy, and undoing the multiplication is hard enough to hide a secret.

Mathematics Facts, sourced to Wolfram MathWorld.

Solve it yourself

This fact is a cryptogram here: 81 letters over 19 different ones, graded medium.

Or go to the puzzle’s own page first.

What it means

This asymmetry is what public key cryptography rests on. Anyone can be handed the product and use it to lock a message, while only the holder of the two factors can unlock one. Multiplying two numbers of a few hundred digits takes a moment; splitting the product back apart has no method fast enough to finish in a human lifetime. No one has proved that a fast method cannot exist, which is the uncomfortable part.

The claim comes from Wolfram MathWorld.

Nearby in the collection

The facts either side of this one.

About as hard as this one

Scored closest to it by the model behind our guide to solving cryptograms.

Play a cryptogram

Every Mathematics Facts cryptogram · All fact collections