Python : Insecure stream encryption

Stream cipher is used. This protection may not be sufficient when encrypting data will be stored on the disk, or if the key is used more than once.

Stream ciphers are vulnerable to “key reuse” attack (the “two-time pad” attack). This means that if the same key is used more than once, an attacker can get an open XOR text, by applying the XOR operation to two different encrypted texts. This will allow to get back the original text.

Sensitive Data Exposure vulnerabilities take the third place in the “OWASP Top 10 2017” web-application vulnerabilities ranking.