contains search in DES encrypted text as in the Vigenere cipher?

Hi all,

I'm faced with the problem of doing subtext search in encrypted text.

Basically I want to be able to test if an encrypted text contains some
known subtext withouth decrypting to the original plaintext.

I know that plain historical substiution ciphers such as the Vigenere
cipher allows this simply by searching for the encrypted subtext within
the encrypted text.

Can this be done in modern ciphers such as DES/3DES or maybe AES?

Simply expressed, the following criteria must be met:

If (plaintext contains subtext) holds true,
then (encrypt(plaintext) contains encrypt(subtext)) must be true.


Ørjan

Orjan Austvold