Section 4.4.4. Robustness

[jedisct1]

allows the user to choose an arbitrary value l >= 0 for every plaintext and then encrypts it into a ciphertext, which is l bits longer.

This is the first sentence of AEZ's abstract, but it actually doesn't mean much on its own. We should rather document the purpose of λ (essentially, a security parameter).

[AndAlBo]

Done. Moved the property to the appendix and added some security reasoning to the definition.