The Vigenere cipher is a method of encrypting or decrypting alphabetic text by using a series of interwoven Caesar ciphers (Caesar Shift), based on the letters of a keyword. In cryptography, Caesar shift is one of the simplest known encryption techniques. It employs a form of polyalphabetic substitution, which is using multiple substitution alphabets.
Base64 encoding and decoding schemes are commonly used to encode binary data. Normally this is required when textual data needs to be transferred over the network or similar media and make sure that data is transferred without any modification. Base64 is commonly used in a number of applications, including email via MIME, and storing complex data in XML. This is a very simple implementation of base64 encoding and decoding in C programming language. There are number of C libraries available for encoding and decoding as well i.e. libb64, OpenSSL Base64, Apple’s Implementations, arduino-base64 etc.