Question { HP, 5720 }

What is the signal?

Answer

In the fields of communications, signal processing, and in
electrical engineering more generally, a signal is any
time-varying or spatial-varying quantity.

Question { HP, 4624 }

What is an interrupt lattency?

Answer

In real-time operating systems, interrupt latency is the
time between the generation of an interrupt by a device and
the servicing of the device which generated the interrupt.
For many operating systems, devices are serviced as soon as
the device's interrupt handler is executed. Interrupt
latency may be affected by interrupt controllers, interrupt
masking, and the operating system's (OS) interrupt handling
methods.

Question { Bristle Cone, 6386 }

tell me about NGT?

Answer

The nominal group technique (NGT) is a decision making
method for use among groups of many sizes, who want to make
their decision quickly, as by a vote, but want everyone's
opinions taken into account (as opposed to traditional
voting, where only the largest group is considered). The
method of tallying is the difference. First, every member of
the group gives their view of the solution, with a short
explanation. Then, duplicate solutions are eliminated from
the list of all solutions, and the members proceed to rank
the solutions, 1st, 2nd, 3rd, 4th, and so on. The numbers
each solution receives are totaled, and the solution with
the lowest (i.e. most favored) total ranking is selected as
the final decision. There are variations on how this
technique is used. For example, it can identify strengths
versus areas in need of development, rather than be used as
a decision-making voting alternative. Also, options do not
always have to be ranked, but may be evaluated more
subjectively.

Question { HCL, 4753 }

Explain about the Physical Data Model?

Answer

A physical data model (a.k.a. database design) is a
representation of a data design which takes into account the
facilities and constraints of a given database management
system. In the lifecycle of a project it is typically
derived from a logical data model, though it may be
reverse-engineered from a given database implementation. A
complete physical data model will include all the database
artifacts required to create relationships between tables or
achieve performance goals, such as indexes, constraint
definitions, linking tables, partitioned tables or clusters.
The physical data model can usually be used to calculate
storage estimates and may include specific storage
allocation details for a given database system.


The Physical Data Model (PDM) describes how the information
represented in the Logical Data Model is actually
implemented, how the information-exchange requirements are
implemented, and how the data entities and their
relationships are maintained.
There should be a mapping from a given Logical Data Model to
the Physical Data Model if both models are used. The form of
the Physical Data Model can vary greatly. For some purposes,
an additional entity-relationship style diagram will
suffice. The Data Definition Language (DDL) may also be
used. References to message format standards (which identify
message types and options to be used) may suffice for
message-oriented implementations. Descriptions of file
formats may be used when file passing is the mode used to
exchange information. Interoperating systems may use a
variety of techniques to exchange data, and thus have
several distinct partitions in their Physical Data Model
with each partition using a different form.

Question { 3517 }

What's CORBA Security Service?

Answer

``CORBA Security Service'' is one of CORBA core services
specified in CORBA 2.x and higher. Specification of it
defines security functionality interfaces available in a
CORBA ORB.

Question { 3542 }

What's CORBASEC?

Answer

Konstantin Beznosov (December, 1997):

``CORBASEC'' is a shorter and more informal name for ``CORBA
Security Service.''

Question { 3527 }

What's the difference between CORBA Security Service and
CORBASEC?

Answer

Konstantin Beznosov (December, 1997):

There is no difference between ``CORBA Security Service''
and ``CORBASEC.''

Question { Satyam, 5166 }

What is CORBA?

Answer

The Common Object Request Broker Architecture (CORBA) is a
standard defined by the Object Management Group (OMG) that
enables Software Components written in different multiple
computer languages and running on multiple computers to work
together that is which supports multiple platforms.

Question { 3902 }

What is Instant CORBA?

Answer

First published in 1997, Instant CORBA provides a solid,
extremely readable introduction to the world of distributed
objects using CORBA and Java on the Web. Written by three
CORBA experts, this book remains an extremely approachable
introduction to CORBA basics for any manager or programmer
trying to make sense of distributed computing using CORBA
objects, Java, and the Internet.

Question { 3416 }

What is the current version of CORBASEC official
specification?

Answer

Konstantin Beznosov (November, 1998): 1.2

Question { 3273 }

Are there any upcoming updates of the CORBA specification?

Answer

Konstantin Beznosov
(May, 1999): Yes. The text of the new revision 1.5 is
available at http://www.omg.org/docs/ptc/98-12-03.pdf.

Question { 3477 }

What is "Principal", and what is meant by "Principal
authentication"?

Answer

Linda Gricius (March, 1998):

Principal authentication is the process of proving your
identity to the security enforcing components of the system
so that they can grant access to information and services
based on who you are. This applies to both human users of
the system as well as to applications.

A user or application that can authenticate itself is known
as a principal. A principal has a name that uniquely
identifies it.

For human users, the process of authenticating to the system
is informally known as "logging on". In a typical system, an
application is provided to collect information proving the
user's identity. This application is often referred to as
the "user sponsor". In order to successfully authenticate to
the system, it is important that a principal can provide
some proof that it is who it claims to be. Proof of
authentication is usually achieved by demonstrating
knowledge or possession of a "secret" known only to the
"real principal", such as a password or cryptographic key.

It is important that a successfully authenticated principal
can be given some unforgeable evidence that it has recently
authenticated, in order to prevent the principal from having
to continually re-authenticate itself to different parts of
the system. The unforgeable evidence that is returned to
authenticated principals is known as the principal's
credentials.

Question { 4279 }

What are credentials?

Answer

An application uses the credentials object to:
• Inquire about the security attributes currently in the
credentials, particularly the privilege attributes.
• Get and set the accepting options supported/required and
the invocation options supported/required attributes.



Interface Credentials
All Super interfaces:
org.omg.CORBA.portable.IDLEntity, org.omg.CORBA.Object,
java.io.Serializable

All Known Sub interfaces:
ReceivedCredentials, TargetCredentials, TLSCredentials,
TLSReceivedCredentials, TLSTargetCredentials

Question { 3808 }

What are the protocols used by CSI?

Answer

Linda Gricius (March, 1998):

CSI Common Security Protocols define the details of the
tokens in the SECIOP messages. Three protocols are defined:

SPKM Protocol
- this protocol supports identity based policies without
delegation (CSI level 0) using public key technology for
keys assigned to both principals and trusted authorities.
The SPKM protocol is based on the definition in The Simple
Public-Key GSS-API Mechanism, Internet Draft
draft-ietf-cat-spkmgss-06.txt January 1996.
GSS Kerberos Protocol
- this protocol supports identity based policies with
unrestricted delegation (CSI level 1) using secret key
technology for keys assigned to both principals and trusted
authorities. It is possible to use it without delegation (so
providing CSI level 0).

The GSS protocol is based on the IETF GSS Kerberos V5
definition, which specifies details of the use of Kerberos
V5 with GSS-API. It includes updates to RFC 1510; e.g., how
to carry delegation information. It is specified in RFC
1964. This itself is a profile of the Kerberos V5 mechanism
as defined in IETF RFC 1510, September 1993.

CSI-ECMA Protocol
- this protocol supports identify and privilege based
policies with controlled delegation (CSI level 2). It can be
used with identity, but no other privileges, and without
delegation restrictions if the administrator permits this
(CSI level 1), and can be used without delegation (CSI level
0).

Question { 3318 }

Are the any interfaces specified in CORBASEC for
controlling security context by security-aware
applications?

Answer

Extended Question:
Examples of controlling security context could be the
following:

* Switch context, a possibility of "switching
context service" between already established contexts
* Hold-on context in case of mobility
* Close/take-down context
* Re-establish context after hold-on context service
* Refresh context in case of revocation or as the
same operation as Refresh() in SecurityContext