Cryptography refers to the science and practice of securing information by transforming it into a form that is unreadable to unauthorized users while remaining accessible to intended recipients. It plays a central role in cyber security by ensuring confidentiality, integrity, authentication, and non-repudiation of data. In modern computing environments, cryptography is widely implemented using programming languages such as Python because of its extensive libraries, ease of implementation, and strong community support. Python provides modules like hashlib, cryptography, PyCryptodome, and ssl that allow developers and security professionals to implement cryptographic techniques efficiently for protecting sensitive data in networks, databases, and applications. One of the primary data security techniques in cryptography is encryption. Encryption converts plaintext into ciphertext using an algorithm and a key so that only authorized users with the correct key can decrypt and access the original information. Encryption techniques are broadly classified into symmetric encryption and asymmetric encryption. In symmetric encryption, the same key is used for both encryption and decryption. Algorithms such as AES (Advanced Encryption Standard), DES (Data Encryption Standard), and ChaCha20 fall under this category. Python libraries like PyCryptodome enable secure implementation of AES encryption for protecting files, communications, and stored credentials. Symmetric encryption is computationally efficient and suitable for encrypting large volumes of data, but it requires secure key distribution, which can be challenging in large systems. Asymmetric encryption, also known as public key cryptography, uses two different keys: a public key for encryption and a private key for decryption. Algorithms such as RSA (Rivest–Shamir–Adleman), ECC (Elliptic Curve Cryptography), and Diffie–Hellman key exchange are commonly used. Python’s cryptography library supports RSA and ECC implementations, making it easier to build secure communication systems such as encrypted email, secure APIs, and digital certificates. Asymmetric encryption solves