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Public exponent

As explained in Real-World Cryptography

A public exponent is the RSA exponent included in the public key and used for modular exponentiation during encryption.

The public exponent e is published with RSA’s public parameters and raises a message to a power modulo the public modulus during encryption. A small exponent makes encryption fast; 65,537 is a historically common choice. section 6.3.1

A tiny RSA calculation

With message m = 2, public exponent e = 2, and modulus p = 5, encryption computes ciphertext = 2² mod 5 = 4. Real RSA uses a public modulus N = p × q rather than a single prime. section 6.3.1

How Real-World Cryptography covers it

How deep it goes
Explains modular exponentiation, gives a small calculation, and stops short of fully deriving the private exponent.
Examples
Uses m = 2, e = 2, and p = 5 to demonstrate ciphertext = 4.
What it assumes
Assumes familiarity with modular groups and exponentiation while reinforcing their use in RSA.
What you can do after
Evaluate RSA encryption as modular exponentiation using a published exponent and distinguish it from private-key decryption.
How it connects
Connects RSA with the private exponent, public modulus, modular arithmetic, and cyclic groups.

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This explainer was generated by Manning's knowledge graph from the text of Real-World Cryptography. The section links point to the parts of the book it draws on.