1.5 Glossary of used terms


GLOSSARY TERM

DESCRIPTION

SecureUPDATE™

Our flagship suite of products (applications) designed to excel in all aspects of secure software updating.

SecureUPDATE™ file

A SecureDELTA or XtremeDELTA type file. They are both binary diff (differencing) files but the building strategy applied consists in totally different algorithms. See below Data Differencing.

SecureDELTA™

Our flagship application designed to create a binary diff (differencing) file from source and target files. The name comes from the name of the algorithm it uses. See below Data Differencing.

SecureSFX™

Generic title for SecureDELTA™ self-extracting installer.

SecurePATCH™

SecureDELTA™ self-extracting Installer with a dialog-like behavior (also: SecureDELTA™ Installer, Installer Stub, SecureDELTA™ SFX Stub Installer, SecurePATCH™)

SecureWIZARD™

SecureDELTA™ self-extracting Installer with a Wizard like behavior (buttons Back, Next, Finish/Close)

SecureCMDLine™

SecureDELTA™ self-extracting Installer that runs in a command line.

SecurePKG™

SecureDELTA Signing Tool. A standalone executable that could be used to sign/verify SecureUPDATE files from the command line

Secure Encoding

The process to create a SecureUPDATE file. It takes two files, source and target and produces a binary diff file. More info on this page.

Secure Decoding

The reverse process of SecureUPDATE. It recreates an exact replica of the target file, given the source and the binary diff file. More info on this page.

Data differencing

In computer science and information theory, data differencing or differential compression is producing a technical description of the difference between two sets of data – a source and a target. Formally, a data differencing algorithm takes as input source data and target data, and produces difference data such that given the source data and the difference data, one can reconstruct the target data ("patching" the source with the difference to produce the target).

Patch

A patch is a set of changes to a software program or its supporting data designed to update, fix or improve it. This includes fixing security vulnerabilities and/or other bugs, with such patches usually being called bugfixes or just patches. Patches may also be used to improve software functionality, usability or performance.

binary diff file / diff file

In computing, the diff utility is a data comparison tool that calculates and displays the differences between two files. Unlike edit distance notions used for other purposes, diff is line-oriented rather than character-oriented. Implemented with an algorithm like Levenshtein distance which tries to determine the smallest set of deletions and insertions to create one file from the other

SFX / SEA

A self-extracting archive (SFX / SEA) is a computer executable program which contains compressed data in an archive file combined with machine-executable program instructions to extract this information on a compatible operating system and without the necessity for a suitable extractor to be already installed on the target computer. The executable part of the file is known as the stub and the non-executable part the archive

Stub

Referred to it mostly as Stub engine. It is a standalone decoding software program optimized in size and customized to perform different extra tasks, for instance, decode from an attached payload.

Adler32

A checksum algorithm which was invented by Mark Adler in 1995. It is a modification of the Fletcher checksum. Compared to a cyclic redundancy check of the same length, it trades reliability for speed (preferring the latter).

CRC32

A cyclic redundancy check (CRC) is an error-detecting code commonly used in digital networks and storage devices to detect accidental changes to raw data. Blocks of data entering these systems get a short check value attached, based on the remainder of a polynomial division of their contents. On retrieval, the calculation is repeated and, in the event the check values do not match, corrective action can be taken against data corruption.

XtremeDELTA algorithm

An advanced binary diff file creation algorithm, developed by the R & D division of NetLUP Xtreme Technologies, agersoftware's strategic technology partner. More details on this on their website, at https://xtremedelta.com

SecureDELTA algorithm

The advanced binary diff file creation algorithm used by our application with the same name, SecureDELTA. It has been developed by the R & D division of agersoftware.

PEAK MEMORY

The maximum amount of memory which was used by the processes or sub-process that is being reported.

CPU TIME

Total processor time, in seconds, used by a process, since it started. CPU time is an indication of how much processing time that the process has used since the process has started. It is basically calculated by:

CPU Time of Process = Process Uptime * CPU Utilization of Process

LOCAL or TEST PC

(test machine)

The workstation or PC SecureDELTA for Windows is running on. The software has to be either licensed on within the 30 day trial in order to run.

REMOTE or USER PC

(user machine)

User PC is your client's PC. This is the remote machine where you will deliver your SecurePATCH files or the binary diff files created with SecureDELTA application.

Transform

A transformation is an revertible function f that maps a set X to itself, i.e. f : X → X. A transformation may simply refer to any function, regardless of domain.

Redundancy

In Information theory, redundancy measures the fractional difference between the entropy H(X) of an ensemble X, and its maximum possible value. Informally, it is the amount of wasted "space" used to transmit certain data. Data compression is a way to reduce or eliminate unwanted redundancy, while check-sums are a way of adding desired redundancy for purposes of error detection when communicating over a noisy channel of limited capacity.

Entropy

Information entropy is the average rate at which information is produced by a stochastic (randomly determined process) source of data.

MiB

The mebibyte is a multiple of the unit byte for digital information. The binary prefix mebi means 220; therefore one mebibyte is equal to 1048576bytes, i.e., 1024 kibibytes. The unit symbol for the mebibyte is MiB. The unit was established by the International Electrotechnical Commission (IEC) in 1998. 

KiB

The kibibyte is a multiple of the unit byte for quantities of digital information. The binary prefix kibi means 210, or 1024; therefore, 1 kibibyte is 1024 bytes. The unit symbol for the kibibyte is KiB. The unit was established by the International Electrotechnical Commission (IEC) in 1998.