TextHide Server


Typical values


approx. 100 kB text per minute

Memory consumption

approx. 20 MB for the dictionary


German, English, French

Ratio data : text

1:10 to 1:20 (worse with technical terms)

Operating systems

MS-Windows 95/98/NT, Unix (Linux, Solaris); MacOS in planning; others upon request

Can be combined with

encryption programs like PGP; TextHide has its own public-key cryptography integrated (based on RSA [4096 bit key length] and the new Twofish method [256 bit key length])

Target groups / applications:

companies and private persons wishing to transfer data over insecure channels like the Internet or by wireless technology; generally all users of encryption software (data sources or possible media to hide information in: e-mails, network data communication, (chip card) secret numbers, newspaper ads, web pages, ordinary conversations)

Features "TextHide Crypto" (steganography & cryptography):

  • several rephrasing aspects like word order and synonym replacement can be used in such a way that secret information is kept even if an attacker rephrases the text
  • text collections available from the following sectors: vacation, politics, business, jokes, anecdotes, glosses, news/newspaper articles (these texts can be used automatically as banal texts)
  • integrated public key cryptography (encryption with public and secret keys; high security since secret keys are not exchanged); method is based on the RSA method for key exchange as well as the brand-new Twofish method as block cypherer (stream encryption)
  • management of public keys (from correspondent partners) and secret keys
  • integrated in MS-Office: TextHide functionality is available via simple short cuts and via buttons in Microsoft Word
  • gigantically long keys from 48 bit (Netscape key length for "safe" Internet connections in Europe) up to 100 kBytes possible – these keys contain the information for reorganizing the dictionary (which words should be used more or less often); the resulting 1030000 possible variants for rephrasing texts make this an extremely secure method. An attacker with a high performance computer would need in average 1029990 years to decode the right secret message with such a long key by random testing. The earth has been existing for about 5 * 109 years. If 100 000 = 105 high performance computers would be assigned to this problem, they would approximately need 102000 times longer than our earth has been existing. The public key method (RSA) works with up to 4096 bits key length, the block cypher (Twofish) with 256 bits key length.
  • Prevention of false reports / wrong instructions: all messages/reports will systematically get hidden secret messages added. These secret messages can take the form of a validity control code to be checked automatically upon decryption. If the control code is wrong, the message / the instruction will be rejected. Alternatively, for manual validity checking, control words or sentences previously agreed upon can be hidden.
  • Misleading eavesdroppers:
  1. With messages to partners, which contain text as banal as the plainly transmitted text, the opposite or something drastically different of the message that is secretly encoded
  2. Through the use of seemingly unencrypted messages instead of directly detectable encrypted messages

Shortly available features / advantages "TextHide Crypto":

  • several (encrypted) secret messages (for different addressees) can be encoded in the text
  • rephrased text can be compressed down to about 25%. This means that a total inflation (compressed text with secret message hidden : secret data) of about 3 can be reached.
  • it is selectable how strong the synonyms can deviate in their meaning within a group
  • all dictionaries included for German, English, and French
  • interactive rephrasal of texts from passive to active through checkbacks
  • grammar correction
  • rules for punctuation
  • conversion from old to new German spelling convention

Additional features / advantages "Server version":

  • integration of cryptography and steganography (encryption & hiding) in any network environments or as a component in applications
  • adaptation of the method: support functionality for any self-generated dictionaries (any word lists or synonym groups can be converted by a program into the TextHide format), adapted steganographical methods, combinable with encryption and/or data compression
  • free support and update service for 1 year

Available components


  • TextHide program for decoding messages
  • free at www.compris.com (for all supported operating systems)
  • Linux version of TextHide Professional
  • free at www.compris.com
  • Server version with network integration
  • $1490 and above
  • patent license (regional / for application area)
  • at least $5000 individually agreeable
  • service: integration into software or the integration in computer networks
  • $75 per hour

Per package (CD-ROM) we charge an additional $9 for international shipping & handling. This may be more if this basic charge doesn't cover the costs for shipment to remote countries.


Data encryption software (Cryptography)

Compris Intelligence GmbH offers Twofish, the most promising candidate for the new US standard AES (Advanced Encryption Standard) for block cyphers. Twofish which was designed by a team around the crypto expert Bruce Schneier and is supposed to replace the DES (Data Encryption Standard) algorithm which roots back in the seventies. Twofish works with just a single key for encryption and decryption. For key exchange the RSA method for public key Cryptography is used in the Compris Intelligence GmbH implementation.

Known encryption methods with public keys are very slow. This is why the fast block cyphering/encryption methods are used and only their keys will be exchanged through a public key method.


Typical values



(independent of the key length)

Pentium II – 400 MHz



10 MB/second

Speed comparison

(basis: Twofish, 256-bit-key, 16 rounds, 8 cycles):

  • RC5-32/16 (256-bit key, 32 r.., 16 cycles)
  • DES (56-bit-key, 16 rounds., 8 cycles)
  • Triple-DES (112-bit key., 48 r.., 24 cycles)
  • IDEA (128-bit-key, 8 rounds, 8 cycles)

Percent worse as Twofish

  • 37%
  • 137%
  • 541%
  • 309%

Memory demand

10 kB data, 270 kB code size


Feistel network with 16 rounds (bijective function made up of 4 key dependent 8x8 bit S-boxes, as well as additional matrices and encryption functions)

Mathematical security / effort needed for cracking with a 256 bit key length

approx. 1010 years

Best successful crypto attack

5 (of 16) rounds of a Feistel network with 222,5 (= 6 million) known input plain texts with an expense of 251 (= 2,3 * 1015). Computational effort rises exponentially with each additional Feistel network

Supported key lengths

all lengths <= 256 bits, in particular: 128 bit, 192 bit, 256 bit

Key exchange

with RSA method for public key-cryptography (up to 4096 bits key length)

Type of the method

block cyphering with secure key exchange

Minimal data length

16 bytes (smaller data lengths can be brought to that minimal length by adding random data)

Operating systems

MS-Windows 95/98/NT, Unix (Linux, Solaris); MacOS in planning; others upon request

Common combinations

  1. with steganography program like TextHide (after encryption)
  2. with any kind of data compression program (before and sometimes after encryption)

Features / advantages:

  • developed in the USA by a research team around crypto guru Bruce Schneier
  • can be integrated in any kind of network environment or as a component in applications
  • newest, most secure and unpatented technology
  • additional RSA component with key management (to secure the key exchange for Twofish)
  • encoding speed, time for key-specific calculations, code size, RAM consumption (main memory), ROM consumption (for example on a smart card) or amount of gates on a chip can be varied or rather traded off against each other. Increasing one of these values goes along with a worsening of one or more of the other values.
  • method can be implemented on a Smartcard with less than 64 bytes of RAM and even less than 1400 Bytes of ROM; as a hardware solution less than 14000 gates will be needed

Available programming components


  • Software development kit (SDK) with English / German documentation (unlimited number of copies allowed)
  • Above SDK with RSA component and key management (in north America a license is needed, otherwise freely useable)
  • Services of integration in software or of integration in networks
  • $100,-

  • $300,-

  • $75,- per hour







Advanced Encryption Standard; adoption in the year 2001 by NIST (US National Institute of Standards and Technology)


Data Encryption Standard; block cypher; from the seventies


kilobyte; 210 Bytes = 1024 Bytes = 213 Bits


Megabyte; 220 Bytes = 223 Bits


The public key encryption method named after their developers Rivest, Shamir and Adleman


Software development kit

Reserve TextHide / Get informed when new versions are released

Download TextHide Demo

Information & Questions: products@compris.com



Compris Intelligence GmbH
Rheingönheimer Str. 79
67065 Ludwigshafen am Rhein
phone (+49) 0700-COMPRISTel (0700-26677478)
fax (+49) 0700-COMPRISFax (0700-26677473)

Internet: www.TextHide.com

www.compris.com |  TextHide |  Contact/Map |  About Compris Intelligence GmbH