What is a cryptology key

Encryption / Encryption

Encryption is understood to be processes and algorithms that convert data into an illegible form using digital or electronic codes or keys. This process is known as encryption. At the same time, it is ensured that the secret data can only be decrypted again with the knowledge of a key.
Instead of encryption, one also speaks of encryption, which means the same thing.

Encryption algorithm

An encryption algorithm is a mathematical function to which the plaintext and a key are passed. The output is a ciphertext that does not allow any conclusions to be drawn about the plaintext. Only with knowledge of the key can the ciphertext be converted back into plain text using the same mathematical function.
From a good encryption algorithm we know that the functionality of the mathematical function may be known and that the data can only be decrypted with the help of the key. And since the method is known, one knows under which assumptions the method works and can check it and test it for weaknesses. In this way you can ensure that an encryption algorithm is secure enough for a particular application.

Encryption method

An encryption method consists of an algorithm for encrypting and decrypting, as well as a method for key exchange, checking authenticity and integrity.
The known encryption methods are divided into symmetric, asymmetric and hybrid encryption methods. In the hybrid encryption process, a symmetrical and asymmetrical encryption process is combined with one another.

Symmetrical encryption


Symmetrical encryption is also known as the secret key method. It is based on a mathematical function that converts plain text into ciphertext depending on a key (digital code). When decrypting, the ciphertext is converted back into plain text with the same key.
Symmetric encryption is best for encrypting files, directories, and drives. These methods are less suitable for data transmission because you have to take care of a secure key exchange and its distribution.

Asymmetric encryption


Asymmetric encryption is also known as the public key method. The main difference to symmetric encryption is that asymmetric encryption works with two keys (different digital codes). One to encrypt and the other to decrypt. The encryption key is public and the decryption key must remain secret. One also speaks of the public key and the private key.
Both keys are a key pair that belongs to the recipient of a message.
In order for a sender to be able to send an encrypted message to a recipient, the recipient must make his public key known to the sender.

Digital or electronic key

One speaks of digital or electronic keys, which means the same thing. The digital key is a bit sequence, the length of which is specified in bits. All encryption methods require the digital key as an individual component of the encryption.
It is expected from a good encryption process that an attacker without knowledge of the key has no chance of getting to the plaintext. At the same time, you want the sender to be able to encrypt quickly with the help of the key and the recipient to be able to decrypt it quickly.

One criterion for the security of an encryption is the number of possible keys and a manageable number of weak keys. A key with a length of 1024 bits, i.e. a sequence of 1024 zeros and ones, is more secure than a key with only 64 bits.
Even if you know how the encryption works, you would have to try out all possible keys in order to get the right key at some point. Even with a relatively insecure key, the security buffer can be large enough if the length is sufficient. As a rule, the longer a key is, the more difficult it is to obtain encrypted information without a key.

Stream ciphers and block ciphers

In the case of stream ciphers or stream ciphers, the data is encrypted in one piece. However, this type of encryption is not that common. Block ciphers are used much more frequently in encryption.
In the case of block ciphers or block ciphers, the data is encrypted individually and one after the other in blocks of a specified size.

Cryptographic protocols / encryption methods

In order to be able to encrypt effectively it is not enough to have an effective encryption algorithm, but one must also solve the various problems with the transmission of data and communication. For this purpose, various cryptographic procedures are combined. This then results in standardized encryption methods or cryptographic protocols.

How secure is encryption?

The history of cryptography teaches us that new methods cannot be trusted in principle. Most new algorithms are cracked after a short time or a little later, that is, simplification mechanisms are found. Only a few algorithms remain, in which all attacks remained unsuccessful or of a theoretical nature even after years.
Nevertheless, it remains difficult to make statements about which procedures are really safe. At some point every procedure is broken, the keys have to be made longer or the procedures have to be changed.

Encryption is always a balancing act between security and convenience. There is no such thing as absolute security. You can only increase the effort. With encryption you only buy time until someone finds a way to get the plaintext of the encrypted data.
In contrast to often announced reports, secret services are not able to crack any encryption. Strong encryption is safe. The prerequisite is, of course, that the key is long enough, the password associated with the private, secret key is strong enough and the secret key is and remains secret. And that the procedures and implementations have no back doors.
In general, one can say that crypto experts confirm that well and properly implemented encryption is safe. Of course, this only applies provided that the implementations used have no back doors.

Overview: encryption

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