A DATA HIDING SCHEME BASED ON VQ AND SOC

[[abstract]]近年來，由於電腦與網路的通訊技術快速的發展，人們也注意到該如果保護通訊責料的安全。因此，資訊責藏的技術開始被提出與研究。隨著責訊資藏技術的發展，責訊責藏主要被分為二大領域：數位浮水印和隱藏學。數位浮水印是用來保護數位影像的著作權或是顯示擁有人。數位浮水印著重的是將浮水印藏入數位影像復，即使這些數位影像經過了一些常用的數位影像處理，還是能找出數位影像中的浮水影。隱藏學跟數位浮水印不同的是，隱藏學的目標在於將密秘責訊藏入影像中，讓欄截者發現不出異常，以達到密秘通訊的目的。隱藏學的主要議題是如何隱藏入更多的責訊以及如何保持藏入責訊復的偽圖的影像品質。隱藏學根據資訊隱藏方法的不同，主要分為空問域的資訊隱藏法和頻率域的資訊隱藏法。 在本篇論文中，我們提出了一個新的灰階影像的隱藏法基於Vector Quantization compression ( VQ ）和Search 一Order codin 劇SOq 。我們的方法利用4 個編碼簿以及VQ 與SOc 的編碼排列組合，可以在一對VQ 區塊中藏入6 位元的資訊，隱藏的資訊量是Yu 等人方法的兩倍，而且偽圖的影像品質也可以保持跟Yu 等人方法的影像品質一樣

改善Peyravian-Jeffries的遠端使用者認證之方法(Improved Peyravian-Jeffries’s remote user authentication scheme)

[[abstract]]在2006年，Peyravian和Jeffries提出了一個在不安全網路下的安全使用者存取方法。他們基於Diffie-Hellman(DH)的使用者認證協定中，原先的方法強調可以抵擋離線猜測密碼的攻擊，但是卻在隨後被提出無法對抗離線密碼猜測攻擊；同樣的，在密碼更改協定之中也是無法抵抗服務阻斷的攻擊(Denial-of-Service attack)，因此本論文將提出一些改善技術使得他們的方法更加的安全。我們在原本傳送的值加入一個互斥或的運算，使得原來曝露的值無法讓攻擊者知道，藉此來改善原本的方法，而使得系統不會受到上述的兩個攻擊，因此可以增加系統的安全，達到增進系統安全的目的

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies