How to make a Cypher [Encrypting & Decrypting String]

[Reapism]

I would like to know how to make a relatively basic Cypher using a basic algorithm. I have tried many times but fail miserably.

I am very sorry I cannot provide you with a basis of code for you to work of with but hopefully a detailed explanation might do it.

Features of the Cypher.

• Ability to Encrypt & Decrypt String data.
• Ability to customize a password in order to make it harder to decrypt.
• In order to decrypt the recipient must have the password the first user encrypted with.

Here's the trick, Once lets say I encrypt the string "Hello World" and then the encrypted data turns into "47mcsDwej#E3@%#@" and then when I encrypt "Hello World" with the same password again, a new encryption will show up as well as it being able to decrypt itself! So same message that can be of multiple encryptions.