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Cryptography Terminology Transcription

Welcome to our cryptography fundamentals module. In this module, we will discuss definitions and terminology relating to cryptography. Cryptography is the science of securing information. We use mathematical techniques to provide security, such as confidentiality. Data integrity, entity authentication, and data origin authentication. The basic goal of cryptography is to take plain text, which is unencrypted data, and convert it to ciphertext or encrypted data that would not be decipherable to any unauthorized individuals.

When we perform the encryption process we have an algorithm which is our formula for the encryption, and we have a key which is variable depending on who is encrypting the data. During the encryption process, we change the original binary data into a scrambled message. When we decrypt data, we use the same algorithm and the same key to transmit that encrypted data back into it's original form.

The algorithm is a complex mathematical formula which can be used to encrypt and decrypt data. There are two main types of algorithms, symmetric and asymmetric. Crypt analysis is the science of breaking the secrecy that cryptography provides. And a key is just a numeric variable or parameter that can be entered into the algorithm in order to create encrypted data.

Cryptography was originally used to secure written documents. But now we use it on computers to secure our electronic files. We use cryptography to prevent unauthorized disclosure of our sensitive information. To detect tampering or anyone modifying our data. To prevent repudiation in legal documents, which is the ability for a user to claim they did not perform some action.

And also to ensure the confidentiality, integrity, and availability protection of our data at rest, such as files stored on a laptop hard drive or data in transit, such as data we are transmitting across the Internet. The encryption algorithm is similar to a lock, every algorithm has their own design and style, different than the competition, but they all perform a similar task.

Just like traditional locks, there are some that are better than others for certain tasks. We group these encryption algorithms into two general categories distinguished by the keys that they used encryption and decryption. These categories are symmetric and asymmetric. Just like traditional lock manufacturers have different names like Schlage, Kwikset or Master.

Or algorithms have different names, are faster and therefore better symmetric encryption algorithms that have become popular are RC4, AES, IDEA, DES, Triple DES and Blowfish. The more scalable asymmetric algorithms, and scalable just meaning that they grow well in large organizations, Are RSA, ECC, LCOML and Diffie-Helman. And a helpful pneumonic to remember these algorithms is AREAD. The A stands for asymmetric, R stands for RSA, E for the ECC, the second E for and the D for Diffie- Helman. Our cryptographic key that is used to encrypt and decrypt data is typically a string of bits used by the algorithm to provide security. This could be a single large number or groups of numbers that is typically shown to human as a hexadecimal string Plain text is our data files that have not yet been encrypted.

Any unencrypted file on your computer, even if it is not a text file, maybe it is a picture perhaps, can be considered plain text before it is encrypted. We use file extensions to easily map programs to allow easy access for our users. For example, if you click on a dot doc file it will automatically open in Microsoft Word and these files are typically safe in an unencrypted format.

Before you can open an encrypted file, in this traditional program, you would have to decrypt the file first to plain text format before the program can recognize it. The algorithms we use today use many different techniques, like confusion, diffusion, entropy, and cipher block chaining, which make it very difficult for an attacker to decrypt the cipher text without having access to the encryption key.

Depending on the type of encryption we're using, we will either have one key, or two keys. With asymmetric encryption, we have different keys that are used to decrypt and encrypt content. So these keys are mathematically related so one is able to decrypt things that are encrypted with the opposite key.

Here we have RSA and ECC and this is commonly used in our public key infrastructure With symmetric encryption, we use the same key to encrypt the data, and the same key to decrypt the data. These keys are usually shorter, and therefore symmetric encryption is much faster than asymmetric encryption.

The most popular symmetric encryption standard is currently AES Our key space is the range of all possible values used to construct a key. And this key is used for the encryption and decryption of data with an algorithm. Longer encryption keys are much stronger because they have Have a much larger key space and a lot more possible key values.

So it becomes a lot more random and the keys are much harder to break. However, as you use longer keys your overhead will increase and this The system will slow down, so you should only use longer keys if the security of the data dictates it. Otherwise, you would just be slowing down your system, providing enhanced security for data that does not need it.

Are Lifecycle indicates that eventually all crypto systems will be compromised as computers become much more powerful. In order for our crypto system to be effective we must maintain the secrecy of our keys. If an unauthorized individual is able to access the keys, it completely defeats the purpose of encrypting the data.

We should make sure that we're using a very strong encryption algorithm and make sure that we have an appropriate key length or key space For the sensitivity of our data. You wanna remember that people are always the weakest link in our security systems and they might write down their encryption key, they could lose the encryption key, or they could tell it to an unauthorized person, so our users will generally be the weakest link.

All of our encryption systems do have a limited life cycle. However, the systems that we are using today are secure for now, but will need to be reconsidered as computing technology increases in the future. This concludes our Cryptography Fundamentals module. Thank you for watching.

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