Free data encryption program software for linux

Gaim-Encryption uses NSS to provide transparent RSA encryption as a Gaim plugin.
Main features:
- Automatically creates a public/private key pair for you upon loading the plugin
- Automatically transmits your public key to other users.
- Supports 512 - 4096 bit keys.
- Saves keys of known users, and warns you if their public key has changed.
- Embeds all encryption and keys inside HTML, so if the other user doesnt have the plugin, they will get a little message telling them about the plugin, and wont get a screen full of garbage.
- Stores keys in human readable files in your .gaim directory, in case you ever need to copy/edit them by hand. Which you really shouldnt have to do.
- Automatically recognizes if you are chatting with someone who has the plugin- see the Preferences dialog.
- Available for the Windows version of Gaim.
- Modular and extensible. If you want to define a different type of encryption, you can use this plugin as a wrapper to take care of transporting the encrypted binary over the IM pipe.

Eureka Encryption Global Edition contains file encryption, multiple encryption, merge encryption, multiple file encryption, embedded applications (Crypt Words, Steganographer, Interface) and other tools such as a file shredder and scrambler.

Eureka Encryption Global Edition is available for Windows, Mac and Linux. Other applications are available from the website.

TrueCrypt is free open-source disk encryption software.
Main features:
- It can create a virtual encrypted disk within a file and mount it as a real disk.
- It can encrypt an entire hard disk partition or a device, such as USB memory stick, floppy disk, etc.
- Provides two levels of plausible deniability, in case an adversary forces you to reveal the password:
- 1) Hidden volume (more information may be found here).
- 2) No TrueCrypt volume can be identified (TrueCrypt volumes cannot be distinguished from random data).
- Encryption algorithms: AES-256, Blowfish (448-bit key), CAST5, Serpent (256-bit key), Triple DES, and Twofish (256-bit key). Supports cascading (e.g., AES-Twofish-Serpent).
- Based on Encryption for the Masses (E4M) 2.02a, which was conceived in 1997.
Enhancements:
- Access rights are now elevated using sudo.
- Volumes can be dismounted only by the user who mounted it or by root.
- Support for writing data to file-hosted volumes located on devices that use a sector size other than 512 bytes (e.g. new HDD types, DVD-RAM, some flash drives) was added.
- A TrueCrypt volume is now automatically dismounted if its host device is inadvertently removed.
- The maximum allowed size of FAT32 volumes was increased to 2 TB.
- Support for big-endian platforms was improved. 64-bit block ciphers are being phased out; such volumes can still be mounted, but not created.

Data::Region Perl module can define hierarchical areas with behaviors.

SYNOPSIS

use Data::Region;

$r = Data::Region->new( 8.5, 11, { data => PageObj->new() } );
$r->data( PageObj->new() );

foreach my $c ( $r->subdivide(2.5,3) ) {
$a = $c->area(0.25,0.25, 2.25,2.75);
$a2 = $c->area(0.25,0.25, -0.25,-0.25); # as offset from lower right

($t,$m,$b) = $a->split_vertical(2,5,1); # sequential heights
($t,$m,$b) = $a->split_vertical_abs(0,2,7); # absolute offsets
($l,$r) = $a->split_horizontal(2); # $l gets width of 2, $r gets the rest

my($x1,$y1,$x2,$y2) = $a->coords();
my $data = $a->data(); # data inherits from parent, if not set
$a->action( sub { $data->setfont("Times-Bold", 10);
$data->text($x1,$y1, "Some Text");
$data->line( $_[0]->coords() ); # the non-closure way
} );
}
$r->render(); # heirarchically perform all the actions

# Get some info about a region:
($w,$h) = ( $a->width(), $a->height() );
($x1,$y1, $x2,$y2) = $a->coords();
($x1,$y1) = $a->top_left();
($x2,$y1) = $a->top_right();
($x1,$y2) = $a->bottom_left();
($x2,$y2) = $a->bottom_right();

Data::Region allows you to easily define a set of nested (2-dimensional) areas, defined by related coordinates, and to associate actions with them. The actions can then be performed hierarchically from any root of the tree.

Data::Region was written to provide an easy way to do simple page layout, but has, perhaps, more general uses.

Sunrise Data Dictionary is a library for hashtable storage of arbitrary data objects with built-in reference counting and guaranteed order iteration for the C programming language.
Sunrise Data Dictionary library can participate in external reference counting systems or use its own built-in reference counting. It comes with a variety of hash functions and allows the use of runtime supplied hash functions via callback mechanism. The source code is well documented.
The Sunrise Data Dictionary was specifically designed for use within the Afelio and Callweaver telephony servers, the implementation focuses on performance and scalability.
Enhancements:
- This is the initial release of the full API (all header files) and a developer snapshot of the implementation.

twocrypt provides a crypto tool with a deniable encryption option.
twocrypt (2c) is a tool for the ultra-paranoid, providing a traditional crypto, but also an option of deniable (subpoena-proof) encryption. It encrypts one or two files at once.
Each file can be recovered with its respective passphrase, but the presence of more than one file cannot be demonstrated, and the presence of this option alone should not be a credible argument for data hiding.
2c2 is a simple symmetric file encryption utility. It comes with an
interesting optional feature - it is capable to embed an additional file
within an encrypted data. This is done in a way that cannot be detected
without knowing the passphrase protecting the "hidden" file, even if the
password for the primary file is disclosed. The design is such that the
fact of using this method alone does not constitute a credible evidence of
data hiding (IANALBMSUTDO). This kind of encryption is also called
"subpoena-proof" or "deniable".
There is some previous work in this area. There are two popular approaches,
one is to throw away the encryption key, but store some information that
can be used to recover the key with a considerable computation effort
(several years or so). The concept seems to be risky for obvious reasons,
and is also impractical if the data has to remain accessible before the
projected cracking date.
The other approach is to have a number of containers protected with a number of passwords, of which some but not all might be encrypted data (rubberhose does that). I think its needlessly complex, and usually applied to a storage such as a disk drive.
As such, 2c would be the first tool to implement this functionality in a
reasonable and practical fasion, at least I think so.
Enhancements:
- It was possible to tell a two-file result from a single-file output,
_statistically_. This does not mean the question can be answered for a
particular archive, but single-file archives had a tendency to result
in a slightly larger file, and if you have a number of 2c-protected
files for which the primary password has been obtained, it can be
told how you use 2c. The reason for that was slightly broken compressed
pad length logic.
Severity: medium
- As a cryptographic safeguard, the random pad stream now consists of
a random, compressed file of a random length, followed by true garbage.
This is to mimick second file scenario more closely, so that if the
encryption proves weaker than originally thought, and some statistical
properties of a stream can be deduced, theres no exposure. Version
1 always used a full-length compressed pad, which was silly in that
its not that common to store perfectly-fit secondary files.
Severity: hypotetical issue
- In v1, random chunk would seldom get compressed, because the compression
algorithm resorted to storing uncompressed data if compression would
result in output bigger than input. This is not a flaw per se, but
defeats a minor safeguard intended to mimick a file that would often
be compressible. Now, encryption of all blocks is forced, even though
it might be less efficient.
Severity: hypotetical issue
- Input blocks are now split randomly to avoid placing compression
headers and other known structures at constant locations. This is just
another arbitrary safeguard for the algorithm.
Severity: hypotetical issue
- per Jamess suggestion, I added a counter to the PRNG generator
internal state. This prevents a hypotetical (although *extremely*
unlikely) generator stall scenario. This spectacularly breaks v1
compatibility, blame James ;-)
Severity: low

Data::ICal::Entry::Journal is a Perl module that represents a journal entry in an iCalendar file.

SYNOPSIS

my $vjournal = Data::ICal::Entry::Journal->new();
$vjournal->add_properties(
summary => "Minutes of my party",
description => "I cried because I wanted to.",
# Dat*e*::ICal is not a typo here
dtstart => Date::ICal->new( epoch => time )->ical,
);

$calendar->add_entry($vjournal);

A Data::ICal::Entry::Journal object represents a single journal entry in an iCalendar file. (Note that the iCalendar RFC refers to entries as "components".) It is a subclass of Data::ICal::Entry and accepts all of its methods.