Skip to content
CoreSource checked

OAEP Padding

OAEP Padding adapts public-key encryption or signatures to safer randomized encodings.

Quick Facts

Compact metadata for implementation and discovery.

Category
Cryptography
Difficulty
Intermediate
Family
Encryption Padding
Tier
Core
Status
Verified
Review
Source Checked
Sources
1
Formulas
0
Relationships
1
Code example
Ready
Visualization
Ready
Aliases
RSA-OAEP

Overview

OAEP Padding is a cryptographic method that protects confidentiality, authenticity, or integrity with a defined primitive or protocol step. It should be used only as part of a well-defined protocol with correct parameters and key handling.

Core Concepts

key materialsecurity parameterverification ruleverification

Quick facts

Complexity

Runtime and memory behavior at a glance.

Best

O(n)

Average

O(n)

Worst

O(n)

Space

O(1)

When to Use

  • Use OAEP Padding only when the protocol calls for this specific primitive or construction.
  • Use it when a vetted implementation is available and parameter handling can be enforced.

When Not to Use

  • Avoid custom protocol combinations around this primitive.
  • Avoid when nonce, key, padding, or parameter requirements cannot be enforced.

What It Does

  • Computes encryption padding within Encryption Padding workloads (O(n) time, O(1) space).
  • Works by It should be used only as part of a well-defined protocol with correct parameters and key handling.
  • Maintains key invariants across key material, security parameter, verification rule.

Use Cases

  • Secure communication
  • Authentication
  • Key management

Inputs

  • Message or secret
  • Key material
  • Nonce, salt, or public parameters

Outputs

  • Ciphertext, tag, key, signature, or proof
  • Verification result

Pseudocode

  1. 1.Validate keys, nonces, and required parameters
  2. 2.Apply the primitive's block, group, hash, or verification operation
  3. 3.Combine intermediate values according to the construction
  4. 4.Return the ciphertext, tag, key, signature, proof, or verification result

Canonical Example

Input
message = 'pay 10', key material = provided, nonce or public parameters = provided
Output
protected value or verification result
Explanation
OAEP Padding applies its defined cryptographic operation without inventing extra protocol steps.

Implementation Notes

  • Use vetted implementations for low-level primitives.
  • Validate parameter lengths, nonce handling, and authentication failure behavior explicitly.

Common Pitfalls

  • Reusing nonces, salts, or ephemeral values can break security assumptions.
  • Treating a primitive as a full protocol invites key-management and authentication mistakes.

Interactive Mechanism Walkthrough

Graph Frontier & Edge Relaxation

Show messages, keys, nonces, and verification values moving through the cryptographic construction.

OAEP Padding mechanism walkthrough step 1 of 4suvwxt
Step 1 of 4: Validate keys, nonces, and required parameters
crypto

Notes

OAEP Padding operates in O(n) time and O(1) space within the Encryption Padding family. Often compared with RSA and PSS Signature Padding.

Sources (1)

What each reference supports for this entry.

RFC 8017

Documentation

Specifies RSA encryption and signature schemes including OAEP and PSS, supporting OAEP Padding.

Open source

Explore Next

Good next jumps from the relationship graph, ranked for useful discovery.

Conceptual neighborRSA

OAEP Padding and RSA address nearby cryptography problems but make different implementation tradeoffs.

Tags

CryptographySecurityPublic Key