Encrypt & Check
Encrypt One Integer
RSA encryption is modular exponentiation with the public exponent and modulus. The ladder exposes each exact row for one tiny message integer.
highlighted = computed this step
Why encryption is modular exponentiation
RSA encryption raises one message integer to the public exponent and reduces modulo n. The ladder shows every square and multiply row instead of hiding the power.
c=memodn
Use the public key
The message integer is 7, the public exponent is 3, and the modulus is 55.
m=7,e=3,n=55
Read the ciphertext
The recomputed final ladder result is ciphertext 13. Anyone with n and e can do this operation.
73mod55=13
Summary
Encryption maps message 7 to ciphertext 13. Exact arithmetic on deliberately tiny toy keys; real RSA uses 2048+ bit primes with padding, and timing/side-channels are not modeled here.
c=13