HDCP规格说明v1.4：高带宽数字内容保护系统

5星 · 超过95%的资源需积分: 15 152 浏览量更新于2024-08-02 收藏 519KB PDF 举报

"HDCP Specification Rev1.4" HDCP（High-bandwidth Digital Content Protection，高带宽数字内容保护）是一种数字版权管理技术，主要用于保护通过数字接口传输的高清视频内容，防止未授权的复制和分发。HDCP v1.4是该系统的一个修订版本，发布于2009年7月8日，由Digital Content Protection LLC（数字内容保护公司）制定。这个版本的目标是确保从源设备（如蓝光播放器、游戏机或卫星接收器）到显示设备（如电视或投影仪）的信号链路中，内容的安全性。 HDCP系统基于加密技术，其核心是加密密钥交换和验证过程。在设备之间的连接建立时，发送方（源设备）会向接收方（显示设备）发送一组加密的密钥和验证信息。如果接收方能够正确解密并验证这些信息，那么它们之间的通信就被认为是安全的，可以进行未加密的高清内容传输。否则，发送方将拒绝传输，以防止内容被未经授权的设备捕获。在HDCP v1.4中，有几个关键的技术特点和改进： 1. **加密算法**：HDCP使用了特定的加密算法来保护内容，虽然具体细节通常不对外公开，但可以推测它可能涉及对称密钥加密和公钥基础设施（PKI）的某些元素，以确保只有合法的接收设备能够解密信号。 2. **设备认证**：每个HDCP兼容的设备都拥有一个唯一的56位密钥，称为HDMI密钥或AKS-V。这些密钥由HDCP授权机构分发，并存储在设备的硬件安全模块中。设备间的数据交换依赖于这些密钥进行安全的相互认证。 3. **限制级联**：HDCP v1.4允许最多7个设备级联，以支持复杂的家庭娱乐系统。这意味着从源设备到最终显示设备的信号路径可以通过多个中间设备（如切换器或放大器）而不会降低安全性。 4. **兼容性**：此版本的HDCP设计与多种数字接口兼容，包括HDMI（高清晰度多媒体接口）、DVI（数字视频接口）以及其他可能支持高清内容传输的接口。 5. **出口管制**：由于涉及到加密技术，HDCP的实施可能受到美国、日本和其他政府的出口控制。这表明使用这些技术可能需要遵守特定的法规。 6. **知识产权**：HDCP规范中的加密和安全功能是Intel Corporation的知识产权，其他品牌和名称则归各自所有者所有。Silicon Image Inc.对这个规范的发展做出了贡献。 HDCP v1.4的实施对于保护高清内容免受非法复制至关重要，特别是在高清视频内容日益普及的时代。然而，随着技术的发展，如HDCP v2.0和v2.2的出现，提供了更强的加密和安全特性，以应对新的破解威胁和更高的分辨率需求。尽管如此，HDCP v1.4仍然是许多现有设备中不可或缺的一部分，确保了旧设备与新内容的兼容性。

High-bandwidth Digital Content Protection System 8 July 2009

Revision 1.4 Digital Content Protection LLC

Page 15 of 90

depending upon whether ADVANCE_CIPHER mode is enabled (see below). However, the frame counter

does not advance while the HDCP device is in the HDMI AVMUTE state, and does not resume advancing

after HDMI AVMUTE state until the first encrypted frame. K

is a 56-bit key used to initialize the HDCP

cipher for encryption or decryption of the HDCP Content. M

is a new 64-bit initialization value for the

HDCP cipher. R

is a 16-bit value used for link integrity verification, and is updated for every 128

frame

counter increment, starting with the 128

. The HDCP Transmitter verifies R

' against its own calculations to

insure that the video receiver is still able to correctly decrypt the information. This verification is made at a

minimum rate of once every two seconds. Synchronous reading of Ri every time it changes (every 128

frame) is also acceptable in lieu of asynchronous polling. (Synchronous reading in the frame prior to Ri

update and shortly after 1 millisecond of the Ri update also provides a method of detecting frame counter

mismatch between HDCP transmitter and HDCP receiver when either device does not support Enhanced

Link Verification). It is required that the R

' read operation complete within 1 milliseconds from the time

that it is initiated by the HDCP Transmitter. Failure for any reason causes the HDCP Transmitter to

consider the HDCP Receiver to be unauthenticated.

In order to enhance the detection of the loss of encryption synchronization, the HDCP Transmitter and

Receiver may optionally support Enhanced Link Verification, in which a computation to aid verification of

cipher synchronization is performed when a specific video pixel is processed. For every 16

frame counter

increment, the decrypted value of channel zero of the first pixel is combined with the least significant byte

Rj using the XOR operation, and the result is made available on the Pj port. If this feature is supported by

an HDCP Receiver, the Bcaps bit 1.1_FEATURES is set and the Pj’ port is always updated. The HDCP

Transmitter may optionally support reading and verifying the Pj’ value against an internally generated Pj

value. However, unless a minimum of three successive mismatches of stable values occur, this is

considered to be a pixel transmission error and not an authentication or synchronization error. In addition,

the mismatched Pj values must be sampled more than once in the same manner as the Ri value. (see

Appendix C). Note that the frame counter may advance on unencrypted frames if ADVANCE_CIPHER

mode (see below) is enabled, in which case the least significant byte Rj and the pixel data is captured every

frame. However, if ADVANCE_CIPHER is not enabled, these values are updated on every 16

encrypted frame.

ADVANCE_CIPHER mode is an optional mode in which the cipher state and frame counter is advanced

for every frame in DVI mode, or for every frame when not in AVMUTE state for HDMI mode, regardless

of whether encryption is enabled or disabled. The HDCP Receiver indicates this capability by setting the

1.1_FEATURES Bcaps bit, and the HDCP Transmitters enables it by setting the

ENABLE_1.1_FEATURES bit in the Ainfo byte. The frame counter is first updated to a value of 1 when

the first ENC_EN is sent or received after authentication, and thereafter incremented every frame, until

SET_AVMUTE is set (in HDMI mode). The cipher state is not advanced if HDMI mode AV_MUTE is

active, and resumes advancing with the first ENC_EN frame after HDMI CLEAR_AVMUTE.

Note: An HDMI-capable HDCP Transmitter that has enabled AC (by writing 1 to

ENABLE_1.1_FEATURES bit of AInfo) may need to re-authenticate after sending an AVMUTE to the

HDCP Receiver, since the HDCP Receiver may have ignored the HDMI General Control Packet that

contained the Set_AVMUTE command, causing the loss of HDCP cipher synchronization.

2.3 HDCP Transmitter State Diagram

The HDCP Transmitter Link State Diagram and HDCP Transmitter Authentication Protocol

State Diagram (Figures 2-5 and 2-6) illustrate the operation states of the authentication

protocol for an HDCP Transmitter that is not an HDCP Repeater. For HDCP Repeaters, the

downstream (HDCP Transmitter) side is covered in Section 2.5.

A variety of events are involved in the transmitter’s decision to begin authentication or to

transmit video. Some examples of such events may include HDCP_HPD (HDCP Hot Plug

Detect) of an attached HDCP Receiver, completion of certain phases of the operating system,

a software request, and mode settings. HDCP receivers are not required to authenticate until

presented with a video signal. When an HDCP Receiver acknowledges an I

C register read, it

High-bandwidth Digital Content Protection System 8 July 2009

Revision 1.4 Digital Content Protection LLC

Page 18 of 90

Transition H1:H2. Immediately after transitioning to DVI mode, the transmitter should begin

sending an unencrypted video signal. This signal may be required before the registers of the

HDCP Receiver are visible to the HDCP Transmitter.

Transition H1:H3. Immediately after transitioning to HDMI mode, the transmitter should

begin sending a video signal. This signal may be required before the registers of the HDCP

Receiver are visible to the HDCP Transmitter.

Transition H2:A0, H3:A0. If content protection is desired by the Upstream Content Control

Function, then the HDCP Transmitter waits for the availability of an Active HDCP Receiver.

State A0: Wait For Active Receiver. In this state the HDCP Transmitter enables video to a

non-HDCP receiver with HDCP Encryption disabled. If no low value content is available or

appropriate, a “blue screen” or informative on-screen display should be transmitted. The

transmitter must repeatedly attempt to read an HDCP register, at least once every 2 seconds

and preferably much more often. Note that in most cases, if the user is watching video from a

different input, the HDCP_HPD signal will still be asserted but the HDCP Receiver’s

registers will not be readable. Upon switching to the HDCP input, the user will wish to see

valid video within a fraction of a second or they may conclude that the HDCP input is not

connected and immediately switch to another input. For this reason, a valid video screen

should at all times be transmitted whenever HDCP_HPD is asserted and authentication should

be started immediately after detecting a valid Bksv (Transition A0: A1).

Transition A0:A1. The successful read of an I2C HDCP register initiates the authentication

protocol.

State A1: Exchange KSVs. In this state, the HDCP Transmitter generates a 64-bit pseudo-

random value (An) and writes that value to the HDCP Receiver. The transmitter reads the

Bcaps register and determines the transport operating mode (DVI or HDMI). If necessary, it

sets Ainfo in the HDCP Receiver to determine the options that will be in effect prior to writing

its KSV (Aksv) to the HDCP Receiver. The HDCP Transmitter also reads the HDCP

Receiver’s KSV (Bksv) and the REPEATER status bit necessary for cipher initialization.

Generation of An using the HDCP Cipher is described in section 4.5.

Transition A1:A0. Failure to read Bksv containing 20 zeros and 20 ones is considered a

protocol failure and causes this state transition to State A0.

Transition A1:A2. The random value An and HDCP Transmitter KSV have been written, and

a valid HDCP Receiver Bksv and REPEATER bit have been read. HDCP Transmitter has

confirmed that Bksv contains 20 ones and 20 zeros.

State A2: Computations. In this state, the HDCP Transmitter computes the values Km, Ks,

and R

, using the HDCP Transmitter’s Device Private Keys, Bksv read during State A1,

and the random number An written to the HDCP Receiver during state A1.

Transition A2:A3. When the computed results from State A2 are available, the HDCP

Transmitter proceeds to State A3.

State A3: Validate Receiver. The HDCP Transmitter reads R

' from the HDCP Receiver and

compares it with the corresponding R

produced by the HDCP Transmitter during the

computations of State A2. If R

is equal to R

', then HDCP Encryption is immediately

enabled. The verification timer is set up to generate timer events at the nominal rate of once

every two seconds, plus or minus one-half second. The HDCP Transmitter must allow the

HDCP Receiver up to 100 ms to make R

' available from the time that Aksv is written. The

HDCP Transmitter also checks the current revocation list for the HDCP Receiver’s KSV

Bksv. If Bksv is in the revocation list, then the HDCP Receiver is considered to have failed the

剩余89页未读，继续阅读

windyzhao

粉丝: 0
资源: 2

HDCP规格说明v1.4：高带宽数字内容保护系统

HDCP_Specification Rev1_3.0

HDCP specification

HDCP Specification Rev1_4_Secure

java毕设项目之ssm基于SSM的高校共享单车管理系统的设计与实现+vue(完整前后端+说明文档+mysql+lw).zip

YOLO算法-贴纸检测数据集-212张图像带标签-部分覆盖-未涵盖-完全覆盖.zip

zigbee CC2530无线自组网协议栈系统代码实现协调器按键控制终端LED灯和继电器动作.zip

手语图像分类数据集【已标注，约2,500张数据】

CNCAP 2024打分表

基于小程序的智慧校园管理系统源代码（java+小程序+mysql+LW）.zip

【图像去噪】基于matlab PolSAR GWLS滤波器图像去噪【含Matlab源码 9937期】.zip

最新资源