Security (IPSec) Encryption-CHS版

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术语解释:

Advanced Encryption Standard (AES):高级加密标准,使用128,192,256位长的KEY来加密128,192,256位长的数据块,可以作出9种组合

Authentication Header (AH): 验证头部,一种安全协议,只 是用来验证头部和防重发.不对实际用户数据部分加密.可配合ESP使用.

Authentication:IPsec框架种的一个功能,用来验证数据完整性,并确保数据在传输过程中没有被篡改,同时也可用来验证数据来源的合法性(验证数据来源).

Certification Authority (CA): 权威认证.第三方受信机构.提供CA证书或发布不信任认证.

Certificate:一个包含标志身份和公钥的加密签名对象

Certificate Revocation List (CRL): 不信任列表,由CA颁布的.

Crypto map: 加密映射,CISCO IOS的一个配置功能语句,提供3个主要功能:一,选择需要加密的数据流(通过调用ACL),二,定义策略(通过调用转换集),三,设置对等体

 Data integrity: 数据完整性机制,通过密钥或公钥确保数据传输过程中没有被篡改.

Data confidentiality: 数据机密性,通过加密或者只让伙伴知道KEY值的方法来保证数据不被其他人读取.

Data origin authentication: 数据源验证,一种安全服务,确保数据是来自正确的发送方,服务要求数据完整性+KEY分发机制(一个密钥只能是发送和接受方知道)

Data Encryption Standard (DES): 数据加密标注,使用密钥加密分组,CISCO-IPSEC使用56位长密钥加密分组

Diffie-Hellman:一种确保共享KEY安全穿越不安全网络的方法,它是OAKLEY的一个组成部分.

Encapsulating Security Payload (ESP): 封装安全有效负载,一种提供数据加密的协议,同时支持验证和防重发功能,它完整封装用户数据,可独自使用或与AH配合使用.

Hash: 哈西,散列算法,将变长分组转化成定长摘要.CISCO在IPSEC中使用SHA (Secure Hash Algorithm )和MD5(Message Digest 5)两种方法.

HMAC:使用SHA,MD5进行消息验证的一种机制.

Internet Key Exchange (IKE): internet key交换.,一种在Internet Security Association and Key Management Protocol (ISAKMP) 框架中使用Oakley和SKEME协议组的混合协议.IKE通常用来确定一个共享的安全策略和对需要KEY 的KEY服务的验证,在IPSEC流量能通过之前,先要对router/firewall/host 这些对等体进行身份验证.可以在双边手工输入预共享(pre-share)ke'y或者通过CA获得KEY,通过双边协商双边获得统一IKE的SA,建立初步的安全通道,为接下来的IPSEC作准备.

Internet Security Association and Key Management Protocol (ISAKMP):一种协议框架,定义一种KEY交换和安全策略协商的

Message Digest 5 (MD5):MD5消息摘要,和SHA一样从MD4发展而来的,产生一个128位长的摘要,SHA比MD5更安全,但更耗资源.

Oakley: 一种KEY交换协议,它的一个基本机制就是Diffie-Hellman KEY交换算法

Perfect Forward Secrecy (PFS): PFS ensures that a given IPSec SA key was not derived from any other secret (like some other keys). In other words, if someone breaks a key, PFS ensures that the attacker is not able to derive any other key. If PFS is not enabled, someone can potentially break the IKE SA secret key, copy all the IPSec protected data, and then use knowledge of the IKE SA secret in order to compromise the IPSec SAs setup by this IKE SA. With PFS, breaking IKE does not give an attacker immediate aclearcase/" target="_blank" >ccess to IPSec. The attacker needs to break each IPSec SA individually. The Cisco IOS IPSec implementation uses PFS group 1 (D-H 768 bit) by default.

Replay-detection: A security service where the receiver can reject old or duplicate packets in order to defeat replay attacks (replay attacks rely on the attacker sending out older or duplicate packets to the receiver and the receiver thinking that the bogus traffic is legitimate). Replay-detection is done by using sequence numbers combined with authentication, and is a standard feature of IPSec.

RSA: A public key cryptographic algorithm (named after its inventors, Rivest, Shamir and Adleman) with a variable key length. RSA's main weakness is that it is significantly slow to compute compared to popular secret-key algorithms, such as DES. Cisco's IKE implementation uses a Diffie-Hellman exchange to get the secret keys. This exchange can be authenticated with RSA (or pre-shared keys). With the Diffie-Hellman exchange, the DES key never crosses the network (not even in encrypted form), which is not the case with the RSA encrypt and sign technique. RSA is not a public domain, and must be licensed from RSA Data Security.

Security Association (SA): An instance of security policy and keying material applied to a data flow. Both IKE and IPSec use SAs, although SAs are independent of one another. IPSec SAs are unidirectional and they are unique in each security protocol. A set of SAs are needed for a protected data pipe, one per direction per protocol. For example, if you have a pipe that supports ESP between peers, one ESP SA is required for each direction. SAs are uniquely identified by destination (IPSec endpoint) address, security protocol (AH or ESP), and security parameter index (SPI).

IKE negotiates and establishes SAs on behalf of IPSec. A user can also establish IPSec SAs manually.

An IKE SA is used by IKE only. Unlike the IPSec SA, it is bi-directional.

Secure Hash Algorithm (SHA): A one way hash put forth by NIST. SHA is closely modeled after MD4 and produces a 160-bit digest. Because SHA produces a 160-bit digest, it is more resistant to brute-force attacks than 128-bit hashes (such as MD5), but it is slower.

Transform: A transform describes a security protocol (AH or ESP) with its corresponding algorithms. For example, ESP with the DES cipher algorithm and HMAC-SHA for authentication.

Transport Mode: An encapsulation mode for AH/ESP. Transport Mode encapsulates the upper layer payload (such as Transmission Control Protocol (TCP) or User Datagram Protocol (UDP)) of the original IP datagram. This mode can only be used when the peers are the endpoints of the communication. The contrast of Transport Mode is Tunnel Mode.

Tunnel Mode: Encapsulation of the complete IP Datagram for IPSec. Tunnel Mode is used on order to protect datagrams sourced from or destined to non-IPSec systems (such as in a Virtual Private Network (VPN) scenario).

原文转自：http://www.ltesting.net