PKCS#7 pads input text at the trailing end with k – (l mod k) octets all having value k – (l mod k), where l is the length of the input and k is the block length.

Design a scheme to alter cipher text so that when decryption occurs the padding is left behind (hint: you may increase the length of the cipher text).

Submit:

1. Describe your scheme.

2. Show the padding for a 20-byte plain text file. Insert a screenshot showing the padding from a hex editor.

3. How many bytes of padding are added for a 32-byte file?

4. Show the padding for a 32-byte plain text file. Insert a screenshot showing the padding from a hex editr.