Decrypt string and original string are not equal

Hi, i trying to test the script for a project. But i noted that after decryptation the string is not equal to the original.Why?

This is my code:

var bf = new Blowfish('text code');
        var test = "test";
        var ciphertext = bf.encrypt(test);
        var plaintext = bf.decrypt(ciphertext);

```
    console.log(plaintext);
    alert(test === plaintext);
```

Thanks for help !
