मोनोअल्फाबेटिक और पॉलीअल्फाबेटिक सिफर: सब्स्टिट्यूशन तकनीकें हिंदी में 📚

This video is very important and useful for those persons who are doing preparation for computer network security exam form any university.
This question generally asked in the exams.

For any query please send me a message in comment section.

Good luck for the bright future 👍👍