Free cryptography for kids software for linux

CryptoServer is OpenSource Server-side cryptography tool and run as daemon.

It is already tested in very busy environment and can support over one million transaction an hour.

CryptoServer accept the GPL License and can use it for any purpose as is.

Crypto++ project is a free C++ class library of cryptographic schemes.
Main features:
- a class hierarchy with an API defined by abstract base classes
- AES (Rijndael) and AES candidates: RC6, MARS, Twofish, Serpent, CAST-256
- other symmetric block ciphers: IDEA, DES, Triple-DES (DES-EDE2 and DES-EDE3), DESX (DES-XEX3), RC2, RC5, Blowfish, Diamond2, TEA, SAFER, 3-WAY, GOST, SHARK, CAST-128, Square, Skipjack, Camellia, SHACAL-2
- generic cipher modes: ECB, CBC, CBC ciphertext stealing (CTS), CFB, OFB, counter mode (CTR)
- stream ciphers: Panama, ARC4, SEAL, WAKE, WAKE-OFB, BlumBlumShub
- public-key cryptography: RSA, DSA, ElGamal, Nyberg-Rueppel (NR), Rabin, Rabin-Williams (RW), LUC, LUCELG, DLIES (variants of DHAES), ESIGN
- padding schemes for public-key systems: PKCS#1 v2.0, OAEP, PSS, PSSR, IEEE P1363 EMSA2 and EMSA5
- key agreement schemes: Diffie-Hellman (DH), Unified Diffie-Hellman (DH2), Menezes-Qu-Vanstone (MQV), LUCDIF, XTR-DH
- elliptic curve cryptography: ECDSA, ECNR, ECIES, ECDH, ECMQV
- one-way hash functions: SHA-1, MD2, MD4, MD5, HAVAL, RIPEMD-128, RIPEMD-256, RIPEMD-160, RIPEMD-320, Tiger, SHA-2 (SHA-224, SHA-256, SHA-384, and SHA-512), Panama, Whirlpool
- message authentication codes: MD5-MAC, HMAC, XOR-MAC, CBC-MAC, DMAC, Two-Track-MAC
- cipher constructions based on hash functions: Luby-Rackoff, MDC
- pseudo random number generators (PRNG): ANSI X9.17 appendix C, PGPs RandPool
- password based key derivation functions: PBKDF1 and PBKDF2 from PKCS #5
- Shamirs secret sharing scheme and Rabins information dispersal algorithm (IDA)
- DEFLATE (RFC 1951) compression/decompression with gzip (RFC 1952) and zlib (RFC 1950) format support
- fast multi-precision integer (bignum) and polynomial operations, with SSE2 optimizations for Pentium 4 processors, and support for 64-bit CPUs
- finite field arithmetics, including GF(p) and GF(2^n)
- prime number generation and verification
- various miscellaneous modules such as base 64 coding and 32-bit CRC
- class wrappers for these operating system features (optional):
- high resolution timers on Windows, Unix, and MacOS
- Berkeley and Windows style sockets
- Windows named pipes
- /dev/random and /dev/urandom on Linux and FreeBSD
- Microsofts CryptGenRandom on Windows
- A high level interface for most of the above, using a filter/pipeline metaphor
- benchmarks and validation testing
- FIPS 140-2 Validated
Enhancements:
- This release added VMAC and Sosemanuk, and improved the speed of several other algorithms using x86/x86-64/MMX/SSE2 assembly.
- Random number generators and DSA-like signature algorithms were modified to reduce the risk of reusing random numbers and IVs after virtual machine state rollback.

Cryptonit project is a client side cryptographic tool which allows you to encrypt/decrypt and sign/verify files with PKI (Public Key Infrastructure) certificates.
Main features:
- Encryption/decryption based on highly reliable algorithms
- Signature/verification procedures ensuring tamper-proof documents
- Use of passwords, certificates & smart (chip) cards for file encryption
- Address book for saving and organizing contacts
- Ability to import contacts and their certificates from the corporate directory (LDAP import)
- Multiple user account management
- Interfaces in both English and French
- CRL download
- RSA cryptography (public key cryptography standard)

trfcrypt is an add-on package to the tcl-extension trf. It provides the encryption functionality which was removed from the base package to allow its inclusion on the Tcl/Tk CDROM without violating US export control laws on cryptography.
The C API is layered on top of the trf C API and provides a set of commands for the management, implementation and usage of blockciphers and stream.
Although it is possible to implement ciphers using only the trf C API the code in this package makes it much easier, as general things like the handling of blockcipher modes are done here, thus obviating the need to reimplement them every time. A new cipher just has to provide some information about itself (key sizes) and functions to:
- generate the internal keyschedule from the specified key
- encrypt/decrypt a character or a block of data

TaoCrypt project is a portable, fast, cryptographic library for most needs.
Main features:
- one way hash functions: SHA-1, MD2, MD4, MD5, RIPEMD-160;
- message authentication codes: HMAC;
- block ciphers: DES, Triple-DES, AES, Blowfish, Twofish;
- stream ciphers: ARC4;
- public key cryptography: RSA, DSA, Diffie-Hellman;
- password based key derivation: PBKDF2 from PKCS #5;
- a pseudo random number generator and large integer support.
There is also support for Base 16/64 encoding/decoding, DER encoding/decoding, and X.509 processing.
To build:
./configure
make
To test the build, from the ./test directory run ./test
Enhancements:
- This release includes bugfixes, portability enhancements, and some optimizations.

autocrypt its a set of scripts that use linux hotplug/udev/cryptoapi mechanism to allow you autocrypting a harddrive what do I means by autocrypting : I means using a "rootplug" ie an identification device to activate the possibility of mounting automatically a crypted device.

Youll need such tool if typically you have some data you require to protect whith cryptography and that you want not creating the node "by hand" each time (this require root privileges) look at the following scenario :

you work into a company which data are sensitives
you dont want to encrypt your home using pam crypt because
you dont want to have to setup your workspace each time you come back.

So you dant want to logout, using a screensaver to prevent use of your computer. But while youre loged the data are accessible.... a malicious hacker can login to you box via network and have access to your data....

You can manually create the cryting device mounting and umounting them at demand but this means you have root privilege you can use a special identification device, a "key" that do it for you.... thats autocrypt this solution use the widely available usbkeys/drives to create the unencrypted devices when the key is pluged and to remove it safely when the device is removed.

LibTomCrypt is a comprehensive, modular, and portable cryptographic toolkit that provides developers with a vast array of well known published block ciphers, one-way hash functions, chaining modes, pseudo- random number generators, public key cryptography, and a plethora of other routines. It has been designed from the ground up to be very simple to use. It has a modular and standard API that allows new ciphers, hashes, and PRNGs to be added or removed without change to the overall end application. It features functions for easy handling and a complete user manual which has many source snippet examples.
LibTomCrypt is a fairly comprehensive, modular and portable cryptographic toolkit that provides developers with a vast array of well known published block ciphers, one-way hash functions, chaining modes, pseudo-random number generators, public key cryptography and a plethora of other routines.
LibTomCrypt has been designed from the ground up to be very simple to use. It has a modular and standard API that allows new ciphers, hashes and PRNGs to be added or removed without change to the overall end application. It features easy to use functions and a complete user manual which has many source snippet examples.
LibTomCrypt is free for all purposes under the public domain. This includes commercial use, redistribution and even branching.
Main features:
- Public domain and open source.
- Written entirely in portable ISO C source (except for things like RNGs for natural reasons)
- Builds out of the box on virtually every box. All that is required is GCC for the source to build.
- Includes a 90+ page user manual in PDF format (with working examples in it)
- Block Ciphers
- Ciphers come with an ECB encrypt/decrypt, setkey and self-test interfaces.
- All ciphers have the same prototype which facilitates using multiple ciphers at runtime.
- Some of the ciphers are flexible in terms of code size and memory usage.
- Ciphers Supported.
- Blowfish
- XTEA
- RC5
- RC6
- SAFER+
- Rijndael (aka AES)
- Twofish
- SAFER (K64, SK64, K128, SK128)
- RC2
- DES, 3DES
- CAST5
- Noekeon
- Skipjack
- Anubis (with optional tweak as proposed by the developers)
- Khazad
- Changing Modes
- Modes come with a start, encrypt/decrypt and set/get IV interfaces.
- Mode supported.
- ECB
- CBC
- OFB
- CFB
- CTR
- One-Way Hash Functions
- Hashes come with init, process, done and self-test interfaces.
- All hashes use the same prototypes for the interfaces.
- Hashes supported.
- MD2
- MD4
- MD5
- SHA-1
- SHA-224/256/384/512
- TIGER-192
- RIPE-MD 128/160
- WHIRLPOOL
- Message Authentication
- FIPS-198 HMAC (supports all hashes)
- FIPS pending OMAC1 (supports all ciphers)
- PMAC Authentication
- Message Encrypt+Authenticate Modes
- EAX Mode
- OCB Mode
- Pseudo-Random Number Generators
- Yarrow (based algorithm)
- RC4
- Support for /dev/random, /dev/urandom and the Win32 CSP RNG
- Fortuna
- SOBER-128
- Public Key Algorithms
- RSA (using PKCS #1 v2.1 and PKCS #1 v1.5)
- DH (using ElGamal signatures and simple DH encryption)
- ECC (over Z/pZ, ElGamal Signatures, simple DH style encryption)
- DSA (Users make their own groups)
- Other standards
- PKCS #1 (both v1.5 and v2.0 padding)
- PKCS #5
- ASN.1 DER for INTEGER types.
Enhancements:
- The ECC code was fixed, cleaned, and improved.
- GCM was fixed.
- UTF8 support was added to the ASN1 code.
- The documentation was improved.
- The published version of the manual is included.

paranoy is a simple, lightweight, open-source, fast but overall safe mail client. all its features are privacy and safety-oriented. it has a ncurses interface and a graphical one based on gtk.
it saves mail and configuration files totally encrypted with strong cryptography standard. it supports pop3, imap(TODO) and smtp connections over ssl, mail filtering and threading , attachments , multibox, OpenPGP standard , anonymous remailers and nymservers.
its hightly configurable, easy to use and install, its written in C and it compiles on Linux, all *bsd systems and win32.

paranoy is a mail client like others, but is very safe, including many technics for encryption. The why, you can find it in Why this section. Now, lets take a briefly look on what this stuff do. paranoy downloads mail from a pop3 server with apop authentication, even with ssl, filters it with highly customizable filters, then saves the mail in encrypted way to folders. Configuration files also are encrypted. paranoy can download mail from more accounts, tells you how many new and old messages you got, send messages with gpg support, so ets sign and encrypt your mail. paranoy has a simple ncurses interface and a cool graphical one using gtk (under development) , and features a nice address book with public keys.