The trapdoor
Two large primes build a modulus. Multiplying them is easy. Factoring the product is the hard problem the cryptosystem leans on.
Rivest · Shamir · Adleman · 1977
RSA, on the bench.
RSA key pairs, drawn on the bench.
Operation desk
Control the public pages
Open the desk and sign in with the operator account. A research login does not enter here.
Two PEM blocks
The public key is SPKI. The private key is PKCS#8. The public exponent on this bench is 65537, the usual Fermat prime.
Padding is separate
A raw key is not a message format. Real protocols wrap RSA with OAEP for encryption or PSS for signatures.
Choose a size on purpose
| Bits | Standing | Note |
|---|---|---|
| 1024 | Retired | Factored in public research. Study only. |
| 2048 | Baseline | Still the common minimum. |
| 3072 | Stronger | Often compared with 128-bit symmetric security. |
| 4096 | Archive | Slower to draw. Used for long-lived keys. |
What is stored
- 1. Your name, email, and a hashed password if you register locally.
- 2. Each generation: size, time, SHA-256 fingerprint, and both PEM blocks.
- 3. An activity log administrators can search.