Cryptology

Happy New Year’s everyone. In the next week I want to start discussing the topic of encryption and the different ways in which people’s information is kept secure. In order to do that however, I need to cover some basic concepts of cryptology. Cryptology is the practice of keeping information secret, and has been used since the invention of an alphabet. Since there are entire courses and majors devoted to cryptology and encryption, I will try to explain these concepts in a way that’s simple to understand.

Although the main idea of cryptology is to ensure the content of a message is confidential, there are other aspects of message integrity that must be taken into consideration. Along with ensuring the message is unreadable (encrypted), the sender and receiver also want to be sure the message has not been altered in any way. It is also important to make sure the message was actually sent by the person that the message claims it was sent from.

When a message is encrypted, the original content (plaintext) is made unreadable using an encryption algorithm. This algorithm encrypts the message into ciphertext, which cannot be read by any intruder or eavesdropper. Since the encryption algorithms are known by everyone, including would be attackers, there is another step that must be taken to prevent intruders from decrypting the message. This is why special keys are needed to decipher the original message. There are both private-key and public-key cryptology systems, and I will explain the advantages and disadvantages of both in upcoming posts.

Another important topic in secure communication is authentication, which ensures that the sender of a message is indeed who they claim to be. Authentication also ensures that the message has not been altered in any way since it was sent. The main way that messages are authenticated uses something called a digital signature. Digital signatures are created by using encryption along with other authentication techniques to provide a (theoretically) unforgeable signature that authenticates the message integrity.

In the next week I will explain the different types of encryption, along with the advantages or disadvantages of each type. I will also explain the different ways in which data is authenticated, including a detailed explanation of digital signatures and certificates. Along with these topics, I will also explain how personal information is stored confidentially in a database.