Quick Summary
Decryption reverses encryption, converting ciphertext back to plaintext using cryptographic keys and algorithms.
Decryption is the process of transforming encrypted data (ciphertext) back into its original, readable form (plaintext). It requires the correct cryptographic key and algorithm to reverse the encryption process.
How Decryption Works
- Receive encrypted data (ciphertext)
- Apply the decryption algorithm
- Use the appropriate decryption key
- Obtain the original plaintext data
Key Types for Decryption
| Encryption Type | Key Used for Decryption |
|---|---|
| Symmetric | Same secret key used for encryption |
| Asymmetric | Private key (paired with public encryption key) |
Decryption Challenges
- Key management and secure storage
- Key exchange without interception
- Performance overhead
- Quantum computing threats
- Backwards compatibility
Decryption in Practice
- Browser decrypts HTTPS responses
- Email clients decrypt PGP messages
- Operating systems decrypt disk encryption
- Applications decrypt database fields
Key Points
- Reverses encryption process
- Requires correct key
- Symmetric uses same key
- Asymmetric uses private key
- Restores readable data
- Key management critical