ISO/IEC 11889 defines the Trusted Platform Module (TPM), a device that enables trust in
computing platforms in general. ISO/IEC 11889 is broken into parts to make the role of each
document clear. Any version of the standard requires all parts to be a complete standard.
A TPM designer MUST be aware that for a complete definition of all requirements necessary to
build a TPM, the designer MUST use the appropriate platform specific specification to understand
all of the TPM requirements.
Part 2 defines the principles of TPM operation. The base operating modes, the algorithms and key
choices, along with basic interoperability requirements make up the majority of the normative
statements in part 2.
1.1 Key words
The key words “MUST,” “MUST NOT,” “REQUIRED,” “SHALL,” “SHALL NOT,” “SHOULD,”
“SHOULD NOT,” “RECOMMENDED,” “MAY,” and “OPTIONAL” in this document’s normative
statements are to be interpreted as described in RFC-2119, Key words for use in RFCs to Indicate
Requirement Levels.
1.2 Statement Type
Please note a very important distinction between different sections of text throughout this document.
You will encounter two distinctive kinds of text: informative comment and normative statements.
Because most of the text in this specification will be of the kind normative statements, the authors
have informally defined it as the default and, as such, have specifically called out text of the kind
informative comment They have done this by flagging the beginning and end of each informative
comment and highlighting its text in gray. This means that unless text is specifically marked as of
the kind informative comment, you can consider it of the kind normative statements.
For example:
Start of informative comment
This is the first paragraph of 1–n paragraphs containing text of the kind informative comment ...
This is the second paragraph of text of the kind informative comment ...
This is the nth paragraph of text of the kind informative comment ...
To understand the standard the user must read the standard. (This use of MUST does not require
any action).
End of informative comment
This is the first paragraph of one or more paragraphs (and/or sections) containing the text of the
kind normative statements ...
To understand the standard the user MUST read the standard. (This use of MUST indicates a
keyword usage and requires an action).