Detailed Instructions: Generate a correct and concise answer for the question based on the words in the context.
Q: Context : In cryptography, DES-X (or DESX) is a variant on the DES (Data Encryption Standard) symmetric-key block cipher intended to increase the complexity of a brute force attack using a technique called key whitening.
Question : Which is the basis of DES-X?
A:
Data Encryption Standard