1. Efficient aggregation of encrypted data in Wireless Sensor Network

3. One limitation of this proposal is that the identities of the on-responding nodes need to be sent along with the aggregate to the sink

4. Merkle-Hellman Knapsack Cryptosystem Simple Knapsack Problem 例： 已知 C = 14, A’ = (1, 3, 5, 10, 22) 試求一 Boolean Vector M s.t. Sol ： 計算步驟可在 線性時間 完成；因為 14 < 22 故知此位元為 0 14 > 10 1 4 < 5 0 4 > 3 1 1 = 1 1 所以 M = (1, 1, 0, 1, 0) 此問題可正式描述成： 已知一整數 C 及一具有 Super Increasing 之向量 A’ （所謂 Super Increasing 即 ）

5. Example: Leaf have id i and a i Leaf = (1, 3, 5, 10, 22) = (a 1, a 2, a 3,a 4, a 5 ) Sink got C = 13, => M = (0, 1, 0, 1, 0) Leaf a 2, a 4 don’t responded id1a1k1 id2a2k2 ……...

6. 缺點： a n 的 bit 數最大 修改