I am working with the above mentioned encryption algorith...
DO you think that encrypting an encrypted message several times will increase the security...
I am working with the above mentioned encryption algorith...
DO you think that encrypting an encrypted message several times will increase the security...
Shouldn't you be reading the various cryptography FAQs?
I am.. Even purchased many books.. But none speaks about this.. Only triple DES has slightly the same topic.. But it instead of encrypting again.. it decrypts it with a wrong key(second key) to make it more secure... but i want to know wheather encrypting it twice or many other times makes it more secure...
Well I think that depends on the encryption.
If is something that is done to each letter, like a ceasarian shift, then doing it again won't help. It could still be decrypted by one key, the product of the two used.
If, on the other hand, a character's position in a string is applicable, and is done in a manner that is related to that position, then another layer of encryption would increase the encryptedness, although you get diminishing returns.
For example, a single Q shift on:
Cprog boards are fun
would produce:
V[tph npstfd str gin
Another q shift gives you:
B]yj m[dygf dyt ho,
But if you Q shift this back using -2, in one pass you get:
Cprog boards are fun
So a Q shift is not improved by multiple passes. But, if a letter's position mattered, like for example, a simple incremented shift:
234567890
325648907
And again:
236459078
It now has to be unshifted in two passes, and can be considered safer.