updating DIRECTORY.md

Author: github-actions

DIRECTORY.md

@@ -1,6 +1,9 @@
 
 ## Ciphers
   * [Caesarcipher](https://github.com/TheAlgorithms/Go/blob/master/ciphers/CaesarCipher.go)
+  * [Diffiehellmankeyexchange](https://github.com/TheAlgorithms/Go/blob/master/ciphers/diffieHellmanKeyExchange.go)
+  * [Rsacipher](https://github.com/TheAlgorithms/Go/blob/master/ciphers/RSAcipher.go)
+  * [Xorcipher](https://github.com/TheAlgorithms/Go/blob/master/ciphers/xorCipher.go)
 
 ## Data-Structures
   * Binary-Tree