第15章网络安全主动防御技术与应用-软考吧-您身边的软考专家-www.ruankaoba.com

第15章网络安全主动防御技术与应用

总题数：23题

【52】入侵防御系统IPS的主要作用是过滤掉有害网络信息流，阻断入侵者对目标的攻击行为。IPS的主要安全功能不包括（52）。

真题详情及解析

【53】入侵检测系统放置在防火墙内部所带来的好处是（53）。

真题详情及解析

【71-75】Trust is typically interpreted as a subjective belief in the reliability，honesty and security of an entity on which we depend（71）our welfare.In online environments we depend on a wide spectrun of things，ranging from computer hardware，software and data to people and organizations. A security solution always assumes certain entities function according to specific policies.To trust is precisely to make this sort of assumptions，hence，a trusted entity is the same as an entity that is assumed to function according to policy. A consequence of this is that a trust component of a system must work correctly in order for the security of that system to hold，meaning that when a trusted（72）fails，then the sytems and applications that depend on it can（73）be considered secure. An often cited articulation of this principle is:＂ a trusted system or component is one that can break your security policy”（ which happens when the trust system fails ）. The same applies to a trusted party such as a service provider（ SP for short ）that is，it must operate according to the agreed or assumed policy in order to ensure the expected level of securty and quality of services. A paradoxical conclusion to be drawn from this analysis is that security assurance may decrease when increasing the number of trusted components and parties that a service infrastructure depends on. This is because the security of an infrastructure consisting of many Trusted components typically follows the principle of the weakest link，that is ，in many situations the the overall security can only be as strong as the least reliable or least secure of all the trusted components. We cannot avoid using trusted security components，but the fewer the better. This is important to understand when designing the identity management architectures，that is，fewer the trusted parties in an identity management model，stronger the security that can be achieved by it.
The transfer of the social constructs of identity and trust into digital and computational concepts helps in designing and implementing large scale online markets and communities，and also plays an important role in the converging mobile and Internet environments. Identity management（denoted Idm hereafter ） is about recognizing and verifying the correctness of identitied in online environment.Trust management becomes a component of（74） whenever different parties rely on each other for identity provision and authentication. IdM and Trust management therefore depend on each other in complex ways because the correctness of the identity itself must be trusted for the quality and reliability of the corresponding entity to be trusted.IdM is also an essential concept when defining authorisation policies in personalised services.
Establishing trust always has a cost，so that having complex trust requirement typically leads to high overhead in establishing the required trust. To reduce costs there will be incentives for stakeholders to “cut corners”regarding trust requirements ，which could lead to inadequate security. The challenge is to design IdM systems with relatively simple trust requirements.Cryptographic mechanisms are often a core component of IdM solutions，for example，for entity and data authentication.With cryptography，it is often possible to propagate trust from where it initially exists to where it is needed.The establishment of initial（75）usually takes place in the physical world，and the subsequent propagation of trust happens online，often in an automated manner.

真题详情及解析

【59】信息隐藏主要研究如何将机密信息秘密隐藏于另一公开的信息中。以下关于利用多媒体数据来隐藏机密信息的叙述中，错误的是（59）。

真题详情及解析

【20】数字水印技术通过在数字化的多媒体数据中嵌入隐蔽的水印标记，可以有效实现对数字多媒体数据的版权保护等功能。数字水印的解释攻击是以阻止版权所有者对所有权的断言为攻击目的。以下不能有效解决解释攻击的方案是（20）。

真题详情及解析

【53】数字水印技术是指在数字化的数据内容中嵌入不明显的记号，被嵌入的记号通常是不可见的或者不可察觉的，但是通过计算操作能够实现对该记号的提取和检测。数字水印不能实现（53）。

真题详情及解析

【20】数字水印技术通过在数字化的多媒体数据中嵌入隐蔽的水印标记，可以有效实现对数字多媒体数据的版权保护功能。以下关于数字水印的描述中，不正确的是（20）。

真题详情及解析

【20】数字水印技术通过在多媒体数据中嵌入隐蔽的水印标记，可以有效实现对数字多媒体数据的版权保护等功能。以下不属于数字水印在数字版权保护中必须满足的基本应用需求的是（20）。

真题详情及解析

【33】典型的水印攻击方式包括：鲁棒性攻击、表达攻击、解释攻击和法律攻击。其中鲁棒性攻击是指在不损害图像使用价值的前提下减弱、移去或破坏水印的一类攻击方式。以下不属于鲁棒性攻击的是（33）。

真题详情及解析

【9】数字水印是通过数字信号处理的方法，在数字化的多媒体数据中，嵌入隐蔽的水印标记。其应用领域不包括（9）。

真题详情及解析