**Set the Authentication and Encryption VPN**~ The basics of creating a VPN is authentication, strong encryption and secure key exchange method. Authenticate users, secure exchange of keys to encrypt, and then encrypt the data using the generated key.

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**Authentication is used to validate a user's identity a number of methods that use one or more of:**

Something you have - can play a key card, security card, driver's license, passport or similar. Encryption is a way to get something readable text into a ciphertext some form of algorithmic mapping. Cryptosystems must use complex mathematical algorithms to create a good enough prevent intruders to use a brute force method to calculate the algorithm used.

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**Two common encryption methods are symmetric cryptosystems Systems and Public Key Cryptography:**

**1) Symmetric encryption**

Symmetric encryption is used merely as an identical key to encrypt plaintext and to decrypt ciphertext. The criptador applies the key to the plaintext data resulting in an encrypted text. The decoder reverses the application of the same key for encryption of the text to reveal the data simple. The most common symmetric cryptosystem is the Data Encryption Standard (DES), of which several variants.

**2) Public**

Key encryption systems are much more complex than symmetric encryption systems, such as DES, and are based on mathematical functions, the functions "door-trap" which is frequently used. They include complex mathematical formulas that include support to high-power, modular arithmetic and the products of large prime numbers generally. The algorithms generate an encryption device and an encryption key, the public can be made available, and a decryption algorithm and decryption key, which is kept secret. Mathematical algorithms are so complex that it is not the mechanism decryption can only be produced by the encryption mechanism.