Crypto Intro
Cryptography is the practice of securing communication from third-party access, ensuring that only the intended recipient can access the message. It involves the use of mathematical algorithms to encode and decode information, converting it into a secret code that is unreadable to anyone except the intended recipient.
Some terminology you may find helpful as you proceed:
- Encryption. A process and method which takes plaintext and produces ciphertext that can be sent to another party, or stored. This often requires a key.
- Decryption. A process and method which takes ciphertext, and produces plaintext. This often requires a key to be shared so that you can retrieve the plaintext data.
- Encoding. A process and method which takes plaintext and produces ciphertext that can be sent to another party, or stored. This does not require a key.
- Key. A piece of information (typically a string of letters, numbers etc) which is used as part of an encryption and decryption process. Depending on the cipher, different requirements may exist for the key in size or structure. Sometimes different keys are used to encrypt/decrypt, which we will learn about later.
- Cipher. An algorithm for performing encryption or decryption. Essentially a recipe that can be followed to produce the result. The cipher typically requires a key and the combination can transform plaintext to ciphertext, or back.
- Hashing. This is where a plaintext input has a hashing algorithm applied to it, to produce a fixed length output of seemingly random, but always repeatable output if you follow the same steps. Most commonly used to validate data such as identity.
Main Concepts: