Improve and Secure Your Cipher: Expert Tips and Feedback

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In summary, the conversation discusses a new mathematical cipher and potential security issues with it. There are concerns about the key and potential ways to break the cipher. It is suggested to not send the entire decimal and to make the key longer to improve security. There is also mention of the security of modern ciphers and the importance of a truly random and unique key.
  • #1
anarkest
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  • #2
I don't think the key improves security. It should not be too difficult to look at the fractional parts and decide what numbers are possible keys (depending on how many digits are given). And depending on how many digits you give, you may also clip letters from the end of long words.
 
  • #3
what if the division gives irrational number?
 
  • #4
PrakashPhy said:
what if the division gives irrational number?

What if dividing two integers gives an irrational number?

I dare say you probably don't care what the message is anymore.

The simplest attack on this is obviously the fact that you need a key.

A lot of work might be able to be done to determine what the key is even if somebody doesn't know. For example, if I see that one of your encrypted words is .015 I know that your key must be relatively large, so starts with a letter near the end of the alphabet. I'm sure that some number theory could be used to drive home at possible keys.

There's no real reason to break up your numbers into blocks of 8 besides this cell phone thing. Usually characters are broken up into blocks so that when transmitted you don't give away what the word lengths are. You don't have such a problem here, and it could make it harder to decrypt if you use different length codewords, because then you'll be transmitting a wider range of numbers. This would mean that the intercepting party has no idea how long the codeword is which would probably be a good thingOne good thing is to not send over the whole decimal, which is how you presented it. Otherwise I could simply find what the decimal is in smallest form and then just scale it upwards until the numerator and denominator both fit the pattern necessary for a codeword. I tried that on two of the decimal numbers you had and it doesn't work because you don't get the full number
 
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  • #5
My initial thought is that the security of modern ciphers is such that knowledge of the algorithm, which is typically publicly available, does not jeopardize the security of the cipher. In your case, if I know the algorithm, a simple brute force attack on the key space should crack the cipher, since I need only to multiply each cipher text word with different keys. Now, the security of your cipher certainly improves as you make the key longer. However, now you must also make the world length longer. In the limit that the key becomes equal in length to the plain text message, you have the well known one-time pad, which is indeed provably secure (in the event that your key is truly random and used only once).
 
  • #6
PrakashPhy said:
what if the division gives irrational number?
That can't possibly happen. Both numbers involved in the division are integers, so the quotient will necessarily be rational. By definition, a rational number is the quotient of two integers.
 

1. What is a cipher?

A cipher is a method of encoding or encrypting information to keep it secret. It is a way of converting plain text into a coded message that can only be understood by someone who has the key to decode it.

2. How is a cipher different from a code?

A cipher involves substituting one letter or symbol for another, while a code involves replacing words or phrases with other words or phrases. A code can be cracked by figuring out the meaning of the words or phrases, but a cipher requires knowing the specific substitution pattern to decode the message.

3. How do you create a new cipher?

There are many different methods for creating a new cipher, but some common steps include choosing a key or pattern for substitution, determining the method of substitution (such as a shift cipher or a substitution cipher), and testing the cipher with different messages to ensure it is secure and easy to use.

4. Is it possible to create an unbreakable cipher?

No, it is not possible to create an unbreakable cipher. As long as humans are involved in creating and using ciphers, there will always be a way to decipher them. However, it is possible to create very strong ciphers that are very difficult and time-consuming to crack.

5. How do you know if a cipher is secure?

The security of a cipher depends on how easily it can be cracked. A good cipher should be difficult to break even with advanced technology and techniques. It is also important to test the cipher with different types of messages and see how long it takes to crack. Additionally, it is important to keep the key used for decoding the cipher a secret to maintain its security.

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