Efficient Transcoding and Encryption for Live 360 CCTV System
Round 1
Reviewer 1 Report
This paper presents an efficient transcoding and encryption for Live 360 CCTV system. The proposed system considering the two issues simultaneously is indeed a novel contribution. However, it seems that the currently presented performance evaluation results only concentrate on video transcoding. It is suggested to provide more results for security issue by considering some common attacks, such as cryptographic attacks and plaintext attacks, as well as analyze the security of the proposed system. Some subjective results of decrypted videos with/without correct keys would be also helpful.
Author Response
Thank you for your valuable comment.
- Firstly, video transcoding was completed for testing in a real-world environment at some high schools. We have planned to take experiment for security by applying some network attacks to the system in next months.
- Security analyzing of the proposed system can be explained as strong points and weak points of secure algorithms, which can be used in the proposed system. In our research, we can apply different secure algorithms such as AES, DSA, ARIA, etc. Because the CCTV system for offices in Korea requires applying ARIA as a standard, thus we chose ARIA.
- To analyze the strong points and weak points of secure algorithms, a paragraph has been updated in section 3.2. Additionally, a paragraph has been updated in section 4.2 to show the comparison between AES and ARIA in terms of performance for the proposed system.
- Some subjective results of decrypted video with/without the correct key has been updated in section 4.2.
- We also upgraded the English quality of the revised version.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The article presents a transcoding and encryption proposal for 360 Live 360 CCTV System. Some comments/suggestions follow:
Section 1:
- Line 80. NAL acronym is used but it has not been previously defined. Same for VPS, PPS and SPS acronyms inLine 83.
- Prhase " Consequently, the encryption process for each transcoding thread does not increase the complexity of the system." requires more explanation.
- A paragraph describing the structure of the paper should be included at the end of the section.
* Section 2:
- Line 88, typo -> "wildely" should be "widely".
- Line 124. "Antonio et al". Antonio is the first name of the author (a very common name). I think it would be better to cite him as "DÃaz-Honrubia".
* Section 3:
- Sub-section 3.2. Authors should justify why ARIA is beeing used in their proposal (if provides better security or security than AES, or if it is used only for proving that it can be used in this type of video transcoding systems). Also, a comparison to AES in terms of performance for the proposed system would be interesting for the reader.
- Line 196. "ARIA crypto library was used to encrypt..". ARIA crypto library is not referenced, please do it (it seems to correspond to reference [27]).
* There are several typos and grammatical errors in the manuscript. It should be thorougly revised.
Author Response
Thank you so much for your valuable comments.
* Section 1:
- We added the definition for NAL acronym.
- The phrase "Consequently, the encryption process for each transcoding thread does not increase the complexity of the system." Some sentences have been updated to explain the computational complexity by using Big O notation theory.
* Section 2:
- We fixed as "widely". Thank you for your careful reading.
- Yes, we checked it again. His name should be cited as "Diaz-Honrubia".
* Section 3:
- A paragraph has been updated in section 3.2 to explain that various secure algorithms can be used for the proposed system. We chose ARIA because offices in Korea require using ARIA as a standard. A paragraph has been updated in section 4.2 to show the comparison between AES and ARIA in terms of performance for the proposed system.
- Line 196: we added the reference [27]. Thank you so much for your check.
- We also upgraded the English quality of the revised version.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Authors have addressed my comments. Please, make a final revision of the text to remove some remaining typos.
