Affine Cipher memperbaiki algoritma Caesar Cipher. Caesar Cipher adalah algoritma kriptografi klasik yang pertama kali ditemukan oleh Julius Caesar. Algoritma ini bekerja dengan cara menggeser setiap huruf dalam plaintext sebanyak n posisi. Misalnya, jika n = 3, maka huruf “A” akan menjadi “D”, huruf “B” akan menjadi “E”, dan seterusnya.
Kelemahan Caesar Cipher
Caesar Cipher memiliki beberapa kelemahan, yaitu:
- Kuncinya mudah ditebak. Jika seseorang mengetahui bahwa kunci Caesar Cipher adalah n, maka dia dapat dengan mudah mendekripsi pesan yang terenkripsi.
- Tidak dapat mengenkripsi semua karakter. Caesar Cipher hanya dapat mengenkripsi huruf-huruf alfabet.
Baca juga : Contoh Soal Studi Kasus: Keamanan Pesan Rahasia dengan Kriptografi
Affine Cipher memperbaiki kelemahan Caesar Cipher dengan menambahkan satu kunci lagi. Kunci ini disebut dengan affine transformation. Affine transformation adalah fungsi matematika yang mengubah satu bilangan menjadi bilangan lain.
Affine Cipher bekerja dengan cara?
Affine Cipher bekerja dengan cara mengalikan setiap huruf dalam plaintext dengan kunci pertama, lalu menambahkannya dengan kunci kedua. Hasilnya kemudian dimodulo 26, yaitu dibulatkan ke bilangan bulat antara 0 dan 25.
Misalnya, jika kunci pertama adalah 5 dan kunci kedua adalah 8, maka huruf “A” akan menjadi “D”, huruf “B” akan menjadi “F”, dan seterusnya.
Affine Cipher lebih sulit untuk dipecahkan daripada Caesar Cipher. Hal ini karena kuncinya tidak mudah ditebak. Selain itu, Affine Cipher juga dapat mengenkripsi semua karakter, termasuk angka, simbol, dan tanda baca.
Perbandingan antara Caesar Cipher dan Affine Cipher
Berikut adalah tabel perbandingan antara Caesar Cipher dan Affine Cipher:
| Fitur | Caesar Cipher | Affine Cipher |
|---|---|---|
| Algoritma | Substitusi | Substitusi + Affine transformation |
| Kunci | Satu | Dua |
| Keamanan | Rendah | Sedang |
| Kemampuan enkripsi | Huruf alfabet | Semua karakter |
| Kesulitan memecahkan | Mudah | Sedang |
Masalah di Affine Cipher
Sebagian besar masalah dalam penggunaan algortitma Affine Cipher terletak pada pemilihan kunci enkripsi, perbaikan yang bisa dilakukan adalah:
- Pemilihan Kunci yang Kuat: Pemilihan kunci enkripsi yang kuat sangat penting dalam Affine Cipher. Untuk memperbaiki keamanannya, pastikan untuk memilih kunci enkripsi yang memiliki nilai a yang coprime dengan 26. Ini akan membuat kunci lebih sulit untuk dipecahkan dengan menganalisis frekuensi huruf.
- Menggunakan Teknik Kunci Rahasia yang Kuat: Lindungi kunci enkripsi dengan baik. Jika kunci enkripsi jatuh ke tangan yang salah, sistem enkripsi tidak akan aman. Pastikan kunci enkripsi hanya diketahui oleh pihak yang berwenang.
- Menggunakan Teknik Kriptografi Modern: Affine Cipher adalah salah satu dari banyak teknik kriptografi klasik dan saat ini dianggap sebagai metode enkripsi yang lemah. Untuk mengamankan data dengan baik, lebih baik beralih ke algoritma enkripsi modern seperti AES (Advanced Encryption Standard) atau RSA (Rivest-Shamir-Adleman).
- Menerapkan Teknik Tambahan: Anda dapat memperkuat Affine Cipher dengan menggabungkannya dengan teknik kriptografi tambahan seperti enkripsi substitusi, enkripsi blok, atau teknik pengacakan (randomization) untuk meningkatkan keamanan.
Kelemahan Affine Cipher
Secara umum, Affine Cipher adalah algoritma kriptografi yang lebih aman daripada Caesar Cipher. Affine Cipher dapat digunakan untuk mengamankan data yang tidak terlalu sensitif. Meski demikian Affine cipher tidak aman, karena kunci mudah ditemukan dengan exhaustive search, sebab ada 25 pilihan untuk b dan 12 buah nilai m yang relatif prima dengan 26 (yaitu 1, 3, 5, 7, 9, 11, 15, 17, 19, 21, 23, dan 25).
Selain itu, Affine Cipher juga memiliki beberapa kelemahan, seperti rentan terhadap serangan pencarian terhadap kunci (brute force attack) karena hanya ada 12 pasangan kunci yang mungkin (untuk a) dalam mod 26. Oleh karena itu, dalam konteks kriptografi modern, Affine Cipher biasanya tidak digunakan sebagai metode enkripsi utama karena keamanannya yang terbatas.
Affine cipher mudah diserang dengan known-plaintext attack. Salah satu cara memperbesar faktor kerja untuk exhaustive key search: enkripsi tidak dilakukan terhadap huruf individual, tetapi dalam blok huruf. Salah satu cara memperbesar faktor kerja untuk exhaustive key search: enkripsi tidak dilakukan terhadap huruf individual, tetapi dalam blok huruf
Hiya, I am really glad I’ve found this info. Nowadays bloggers publish just about gossips and web and this is actually frustrating. A good site with exciting content, that is what I need. Thanks for keeping this site, I’ll be visiting it. Do you do newsletters? Can not find it.
Great tremendous things here. I am very glad to see your article. Thanks a lot and i am taking a look ahead to contact you. Will you please drop me a e-mail?
Great blog! Do you have any suggestions for aspiring writers? I’m planning to start my own website soon but I’m a little lost on everything. Would you suggest starting with a free platform like WordPress or go for a paid option? There are so many options out there that I’m completely confused .. Any tips? Appreciate it!
I love how your posts are both informative and entertaining You have a talent for making even the most mundane topics interesting
I visited a lot of website but I conceive this one has something extra in it in it
Lovely just what I was looking for.Thanks to the author for taking his clock time on this one.
Very interesting topic, appreciate it for putting up. “There are several good protections against temptations, but the surest is cowardice.” by Mark Twain.
Great post, I believe website owners should acquire a lot from this weblog its very user pleasant.
I got what you intend,bookmarked, very decent website .
Hey, you used to write magnificent, but the last few posts have been kinda boring?K I miss your great writings. Past several posts are just a bit out of track! come on!
I’ve been exploring for a bit for any high quality articles or blog posts on this sort of area . Exploring in Yahoo I at last stumbled upon this site. Reading this info So i’m happy to convey that I have an incredibly good uncanny feeling I discovered just what I needed. I most certainly will make sure to don’t forget this site and give it a look on a constant basis.
Rattling great information can be found on blog. “Compassion for myself is the most powerful healer of them all.” by Theodore Isaac Rubin.
Howdy! This post couldn’t be written any better! Reading this post reminds me of my good old room mate! He always kept chatting about this. I will forward this page to him. Pretty sure he will have a good read. Many thanks for sharing!
Wonderful website. Lots of useful info here. I am sending it to some friends ans also sharing in delicious. And obviously, thanks for your sweat!
We’re a group of volunteers and starting a new scheme in our community. Your website offered us with valuable info to work on. You have done an impressive job and our whole community will be thankful to you.
What¦s Going down i’m new to this, I stumbled upon this I have discovered It absolutely helpful and it has helped me out loads. I am hoping to contribute & assist other customers like its aided me. Great job.
You made some decent points there. I looked on the internet for the subject and found most guys will go along with with your site.
Hi my friend! I wish to say that this post is awesome, nice written and include approximately all significant infos. I’d like to see more posts like this.
I really like reading through and I think this website got some truly useful stuff on it! .
Good day very nice web site!! Guy .. Beautiful .. Superb .. I will bookmark your web site and take the feeds additionally?KI am happy to search out a lot of helpful info right here in the post, we’d like develop extra techniques in this regard, thanks for sharing. . . . . .
Its superb as your other articles : D, thanks for posting.
I enjoy the efforts you have put in this, regards for all the great posts.
The very root of your writing while appearing agreeable originally, did not sit properly with me after some time. Someplace throughout the paragraphs you actually managed to make me a believer but just for a while. I nevertheless have got a problem with your leaps in assumptions and one would do well to help fill in those breaks. When you actually can accomplish that, I will certainly end up being fascinated.
Great site! I am loving it!! Will come back again. I am taking your feeds also.
I am not really superb with English but I get hold this really easygoing to translate.
You are my inspiration , I have few blogs and often run out from to brand.
When I originally commented I clicked the “Notify me when new comments are added” checkbox and now each time a comment is added I get four emails with the same comment. Is there any way you can remove me from that service? Many thanks!
I am impressed with this website , very I am a big fan .
Thank you a lot for sharing this with all folks you actually realize what you are speaking about! Bookmarked. Kindly also visit my site =). We will have a link exchange agreement between us!
Have you ever thought about writing an ebook or guest authoring on other websites? I have a blog centered on the same information you discuss and would love to have you share some stories/information. I know my readers would value your work. If you’re even remotely interested, feel free to send me an email.
I’d constantly want to be update on new posts on this web site, bookmarked! .
Very fantastic visual appeal on this web site, I’d value it 10 10.
I?¦ve recently started a website, the info you provide on this site has helped me greatly. Thank you for all of your time & work.