“Cryptography” comes from the Greek words kryptos, meaning “concealed, hidden, veiled, secret, or mysterious,” and graphia, meaning “writing”; thus, cryptography is “the art of secret writing.”
Cryptography is the practice of concealing information by converting plaintext (readable format) into ciphertext (unreadable format) using a key or encryption scheme. It is the process of converting data into a scrambled code that is encrypted and sent across a private or public network. Cryptography protects confidential data such as email messages, chat sessions, web transactions, personal data, corporate data, e-commerce applications, and many other types of communication. Encrypted messages can, at times, be decrypted by cryptanalysis (code breaking), even though modern encryption techniques are virtually unbreakable.
Objectives of Cryptography
- Confidentiality: Assurance that the information is accessible only to those authorized to access it.
- Integrity: Trustworthiness of data or resources in terms of preventing improper and unauthorized changes.
- Authentication: Assurance that the communication, document, or data is genuine.
- Nonrepudiation: Guarantee that the sender of a message cannot later deny having sent the message and that the recipient cannot deny having received the message.
Cryptography Techniques Covered in the Learning Path:
- Morse code
- Vigenere cipher
- Base64 Encoding
- MD5 Hash
- SHA256 Hash
- Caesar cipher