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Feb
5
comment What are some approaches to attack an triple key polyalphabetic cipher when the IV key and PT key are known?
The first keyed alphabet is **U P S T A I R B C D E F G H J K L M N O Q V W X Y Z **
Feb
5
comment What are some approaches to attack an triple key polyalphabetic cipher when the IV key and PT key are known?
The IV characters corresponding to the crib are "PIMA" yes? The crib row contents I have are P Y F R A B C D E G H I J K L M N O Q T U V W Z X S R T T <br/> I J K L M N O Q T U V W Z X S P Y F R A B C D E G H X H H <br/> M N O Q T U V W Z X S P Y F R A B C D E G H I J K L S E E <br/> A B C D E G H I J K L M N O Q T U V W Z X S P Y F R F Y Y <br/>
Feb
5
comment Generate random number which should depend on key
@fgrieu You're quite right. Although I'm sure it's more fun to pick holes in other people's answers than it is to craft your own, now you've already expended all this effort, why don't you craft a "proper" answer and see whether it gets accepted eh?
Feb
5
comment Is such a crypto-system available?
@poncho I guess I could have specified that D=E and then f is the inverse as you said.
Feb
5
comment Is such a crypto-system available?
@CodesInChaos 1)No. My definition of f is correct because the post specifies D(k_new,c2)=pt not E(k_new,c2)=pt. Presumably the Decryption function magically obtains the decryption exponent from k_new! 2)Give me an example of inverting f which is not equivalent to factoring the modulus and hence breaking RSA.
Feb
5
answered Is such a crypto-system available?
Feb
5
revised What are some approaches to attack an triple key polyalphabetic cipher when the IV key and PT key are known?
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Feb
5
revised How to check the strength of an encryption algorithm?
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Feb
5
revised How to check the strength of an encryption algorithm?
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Feb
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answered How to check the strength of an encryption algorithm?
Feb
5
answered Why does the recommended key size between symmetric and assymetric encryption differ greatly?
Feb
5
answered What is RSA key normalization?
Feb
5
comment Generate random number which should depend on key
@fgrieu What you say is true. I forgot the lower bit would toggle and should have insisted on an odd $m$. However the level of my answer was appropriate for the question. We both know that any simple scheme based on a linear congruential generator is flawed and therefore "Streetboy" is not looking for something secure but needs instead to be told that he doesn't need to set m to 100 just because he needs numbers in that range. Now give me some upvotes!
Feb
4
revised What are some approaches to attack an triple key polyalphabetic cipher when the IV key and PT key are known?
added 271 characters in body
Feb
4
revised What are some approaches to attack an triple key polyalphabetic cipher when the IV key and PT key are known?
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Feb
4
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Feb
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revised What are some approaches to attack an triple key polyalphabetic cipher when the IV key and PT key are known?
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Feb
4
answered Generate random number which should depend on key
Feb
4
answered What are some approaches to attack an triple key polyalphabetic cipher when the IV key and PT key are known?
Feb
4
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