Revocation

Revocation is essentially the reversal of the processes of authorisation and authentication described above. It can occur for any number of reasons, but among the most common reasons are changes in status of the content item or user or the response to some threat to the system.

基本上，撤回就是前述授權與認證程序的反向過程。發生撤回的情形有各種原因 ， 不過最通常的原因內容或使用者地位變更，或是系統接收到具有某種威脅性的反應。

The change of status situation is a normal occurrence. The authentication system used in institutions of higher education as described above regularly have to accommodate changes in the status of particular students. Clearly, as they leave the institution their institutional privileges are lost and both authority to use the institution’s digital resources as well as the ability to authenticate oneself as an authorised user are revoked.

身分情況變更是一種正常發生的事。前述高等教育機構所使用的認證系統，必須 經常輸入特定學生們身分變更的資料。顯然，當他們離開這個機構，他們就喪失了在 機構中享有的優惠，而他們使用機構數位資源的權限，與經認證為授權使用者的能力，

都會遭到撤回。

Revocation in an academic environment might also occur as a student moves from one academic year to the next; attributes will change accordingly and can be used for reserving certain resources to particular groups of students.

51Information available at <http://www.opensaml.org>.

在學術環境，撤回也可能發生於學生的學年升級時；屬性將會因此變更，而屬性 也可用於對特定學生群體保留特定資源。

Security is the other area where revocation is most commonly provided for. If the system proprietor or administrator perceives that a particular user is attempting to hack the security of the system, it should be possible revoke that user’s ability to access the system.

安全是另一個最常導致撤回的領域。如果系統所有人或管理人發覺特定使用者試 圖破解系統安全，就可能撤回該使用者取用系統的能力。

The principle of revocation is therefore relatively straightforward. The implementation is more complex.

因此，撤回的原則相對上很簡單。而執行則是較為複雜。

First of all, the mechanisms in the system facilitating revocation should be able to respond efficiently to the particular need. The revocation may need to be effected in rapid response to a threat or an attack to the security or integrity of the system; it should occur accurately, ensuring the target is correctly identified and the right action taken. There should be no disruption to other users on the system.

首先，系統的撤回機制應該能夠對特定行為採取有效率的反應。對於系統安全或 完整性的威脅或攻擊，必須以迅速反應實行撤回；撤回必須準確，以確保目標識別與 行動正確無誤。對於系統其他使用者不應有干擾。

Secondly, the ability of the system proprietor or administrator to deny particular users access to the system illustrates the power that the proprietor or administrator wields over the access and use of content as whole. The potential for abuse is significant.

第二，系統所有人或管理人拒絕特定使用者取用系統的能力，顯示出其權力凌駕 於全體的內容取用與使用。而濫用權力的可能性則相當大。

To counter this threat, revocation should only be performed in accordance with clear and well-established policies. There should be clearly stated criteria for exercising the right to revoke a user and for dealing with the consequences of revocation.

為了反制這種威脅，惟有依照清楚明確的政策方能夠實施撤回。關於針對使用者 行使撤回權，以及撤回結果的處理，應該有清楚規定的標準。

CHAPTER 6 第六章

TRUSTED INTERMEDIARIES

具公信力中介者(TRUSTED INTERMEDIARIES)

In this study we have advanced a number of propositions:

在本研究中，我們提出了一些命題：

– That there exist no DRM systems capable of automating the full range of rights management processes customarily required by copyright law;

– 著作權法要求的權利管理程序，是能夠在個案中量身訂製，然而卻沒有

DRM 系統能夠將這種程序完全自動化；

– That where a DRM system is used for managing the copyright in an item of content, the same or a comparable DRM system is required to manage (at least some of) the exceptions to that copyright;

– 使用 DRM 系統管理某一件內容時，該 DRM 系統或類此相當的 DRM 系

統必須管理（至少某些）著作權例外規定；

– That there are a variety of tasks both integral and extraneous to the specific DRM mechanism that have to be performed by some entity or entities to enable the DRM system to function efficiently; and

– 對於特定的 DRM 機制，必須由某個主體執行各種 DRM 內部與外部措施，

使 DRM 系統有效率地運作；且

– That there needs to exist an unbroken chain of trust throughout the automated rights management process; the technology of the system as well as its operational managers have to be trustworthy.

– 在整個自動化權利管理程序，信任環節不能有中斷；該系統的科技與管

理者必須值得信賴。

These propositions lead logically to our final area of enquiry: consideration of the intermediary entities that are required to facilitate the implementation of copyright exceptions through automated rights management systems. We have to reflect on the role of such entities and the requirements of that role.

這些命題在邏輯上導出了我們最後的研究領域：在自動化權利管理系統中，執行 著作權例外規定所必須的中介者(intermediary entities)。我們必須思考這個主體的角色，

以及這個角色應具備的要求條件。

We also suggest a convergence in the role of managing the copyright based exceptions to technically enforced protection and the management (as described in the previous chapter) of the technology required to give effect to those exceptions.

我們也建議，關於技術性保護的著作權例外規定，以及使這些例外規定能發揮作 用的科技，這二者在管理角色上進行合併。

There are few if any precedents for these roles in the copyright field, whether in the administration of rights or exceptions, including compulsory licences. We have therefore to

launch our enquiry from basic assumptions about the likely components of the intermediary role and see what analogues can be found in other fields.

在著作權領域中有一些這種角色的前例，例如在權利上的管理或例外規定上的管 理，包括強制授權。因此我們必須由中介者角色可能內涵的基本假設開始研究，並看 看在其他領域能找到哪些類似者。

A preliminary consideration is the requirement that the intermediary entity, and processes in which it engages, have to be “trusted” in the sense we have adopted throughout this study: the capability of delivering predictable results. The intermediary entity proposition we consider here involves the bringing together or an infinite number of both content providers and end users: all of these have to be able to rely on the role of the intermediary. Content providers need to be assured that content they entrust to the intermediary will be managed and protected in strict accordance with their instructions and the requirements of the law. End users will rely on the intermediary, perhaps exclusively, for access to relevant content and must be guaranteed the sustainability and efficiency of that supply.

中介者與其所從事的程序，在要求條件上的一個基本考量是，必須在本研究所採 取的意義上「可信賴」：產出可預測結果的能力。我們這裡所考量的中介者，涉及無 數的內容供應者與使用者：所有這些人都必須依賴中介者的角色。內容供應者必須確 保，他們委託於中介者的內容，將會嚴格依照他們的指示與法律要求，而受到管理及 保護。終端使用者或許將完全依賴中介者，以取用相關內容，並必須由中介者擔保內 容供給上的持續及效率。

In short, our search is for a basic model for a trusted intermediary to implement through technical measures certain exceptions to copyright in a way that respects fully the rights of content providers and the legitimate expectations of end users.

總而言之，我們所探求的是，能充分尊重內容供應者權利及終端使用者正當期待 ， 以技術措施執行特定例外規定的具公信力中介者(trusted intermediary)基本模型。