cisco dumps 300-101

cisco dumps 300-101.1. Symmetric algorithmsAs mentioned earlier, a symmetric encryption algorithm (also called symmetriccipher) uses the same key to encrypt and decrypt data. Both devices interconnected via VPN need a key (or keys) to smoothly encrypt and decrypt the data protected by the symmetric encryption algorithm. Several commonly used symmetric encryption algorithms are shown below.DESO 3DESOAESOIDEAO RC2, RC4, RC5, RC6OToday, data protected via VPN is generally protected with symmetric algorithms (encryption) because they are faster to execute and consume fewer CPU resources than asymmetric algorithms. As with all encryption, the stronger the key, the more difficult it is for someone without the key to intercept and understand the data. When configuring a key for a VPN, it is often necessary to specify the length of the key. The longer the key, the higher the security. The range of key lengths is typically 112.256 bits. Symmetric encryption algorithms require a minimum key length of 128 bits to be considered secure. Again, the longer the key, the better.2. Asymmetric algorithm Public key algorithm is an asymmetric encryption algorithm. The magic of asymmetric encryption algorithm is that instead of using the same key to encrypt and decrypt, two different keys are used, which are mathematically paired. These two keys are called the publickey and private key, and they form a pair of keys. First, let's use theLet's use an analogy with these two keys.Suppose there is a huge container with a special lock that has two eyes (one large and one small). The magic of this container is that if you lock it with the small key for the small eye, you can only unlock it with the large key for the large eye; or you can lock it with the large key, but you can only unlock it with the small key (isn't that amazing!). . This example fully explains the relationship between the public key and the matching private key (it is up to the reader to decide which is the big key and which is the little key). Using key pairs to "lock" and "unlock" data can be very CPU intensive. Therefore, symmetric encryption algorithms should be used with caution. Asymmetric encryption algorithms can be used to authenticate VPN peers or to generate material for symmetric encryption algorithms to compute keys, and are not typically used to encrypt bulk data. Those two functions are not really common compared to encrypting all user packets (a common occurrence).