GirkovArpa

How to make Vigenere unbreakable

Recommended Posts

If you use multiple keys whose lengths are relatively prime, your effective Vigenere key length is the product of the lengths of all the keys.  Imagine using keys with relatively prime lengths 9, 10, and 11.  Your effective key length would be 1,320 characters long!  Using an easily-remembered phrase that you can break up until lengths of perhaps 29, 30, and 31, you're practically using a one-time pad 26,970 letters long that you can store in your head!

Is there any way to crack such a ciphertext if it's shorter than the effective key length?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.