ENCRYPTION

key concepts of encryption

these are

data privacy

data integrity

authentication

data privacy

concept where Encryption ensures that sensitive information remains confidential and can only be accessed by authorized individuals or systems.

By converting plaintext into ciphertext, encryption protects data from being intercepted or read by unauthorized parties during transmission or storage.

data integrity

key concept where Encryption mechanisms often include tools like cryptographic hashes to ensure data has not been altered, either maliciously or accidentally, during transmission or storage.

Recipients can verify that the data received is exactly as it was sent, ensuring trust in its accuracy.

authentication

concept where Encryption is used to verify the identity of the data sender or the system with which a user is communicating.

Digital signatures and certificates, often implemented using asymmetric encryption, authenticate the source of the data, preventing impersonation or fraud.

type of encryption

these are

symmetric

asymmetric

symmetric encryption

use same key for both encryption and decryption

• Keys must be kept secret to ensure security.

  • Examples: AES, DES, Triple DES.\

    Advantages:
    Fast and efficient for large datasets
    Simpler implementation.

  • Disadvantages:
    Key distribution challenges.
    Single point of failure if the key is compromised.

symmetric-key cryptography

In -_____, the same key is used by the sender(for encryption) and the receiver (for decryption).

The key is shared. Algorithm: DES,3DES

It mainly used for encryption and decryption, cannot be used for digital signatures

often used for long messages

Asymmetric Encryption

Uses a pair of keys: Public key for encryption, private key for decryption.

Examples: RSA, ECC, DSA.

• Advantages:
  Simplifies key distribution (public key can be shared).
  Provides digital signatures for authentication.

• Disadvantages:
  Slower compared to symmetric encryption. Higher computational overhead.

Asymmetric Key Cryptography

• ---

  (Public Key Cryptography)

  • 2 different keys are used

    • Users get the Key from an Certificate Authority

It can be used for encryption and decryption as well as for digital signatures

it is more efficient for short messages

asymmetric-key

An ______ (or public-key) cipher uses two keys: one private (To encrypt data) and one public(To decrypt data).

key process of “Ke# Kd”

• Private Key

• Asymmetric encryption use two keys:

Public Key - to encrypt the data Private Key - to decrypt the data

• These keys are generated together.

• The Public key(s) is distributed freely between the sender and receiver.

• The other is named as ______ and it is kept hidden.

  • The ________ is only used for Decryption and will not be shared between the sender and receiver.

merits

Two parties don't need to have their private keys already shared in order to communicate using encryption.

Authentication

______ and Non-Repudiation are possible. (______ means that you can encrypt the message with my public key and only I can decrypt it with my private key. Non-repudiation means that you can "sign" the message with your private key and I can

verify that it came from you with your public key.)

demerits

• Asymmetric Encryption algorithms are comparatively complex.

• Time consuming process for Encryption and Decryption.

Hybrid Encryption Systems

• Use asymmetric encryption to securely exchange symmetric keys.

  • Example: SSL/TLS protocols

Encryption

it ensures data confidentiality, integrity, and authentication.ensures data confidentiality, integrity, and authentication.

Symmetric Encryption

• Fast, but needs secure key sharing.

Asymmetric Encryption

• Secure key sharing but computationally expensive.