The Caesar cipher, also known as a shift cipher, is one of the simplest forms of encryption. It is a substitution cipher where each letter in the original message (called the plaintext) is replaced with a letter corresponding to a certain number of letters up or down in the alphabet.
In this way, a message that initially was quite readable, ends up in a form that can not be understood at a simple glance.
For example, here's the Caesar Cipher encryption of a message, using a right shift of 13.
Plaintext:
THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG
Ciphertext:
GUR DHVPX OEBJA SBK WHZCF BIRE GUR YNML QBT
As unreadable as the resulting ciphertext may appear, the Caesar Cipher is one of the weakest forms of encryption one can employ.
- The key space is very small. Using a brute force method, one could easily try all (25) possible combinations in order to decrypt the message without initially knowing the key.
- The structure of the original plaintext remains intact. This makes the encryption method vulnerable to frequency analysis - by looking at how often certain characters or sequences of characters appear, one can discover patterns and potentially discover the key without having to perform a full brute force search.
The container can be found at:
Okqpd pdenpu bkqn zacnaao psahra zkp bera dqjznaz wjz pdenpu bkqn.
Awop kja dqjznaz wjz bebpu zacnaao bebpu aecdp zkp bera dqjznaz wjz pdenpu psk.
