While getting my Masters degree at CalTech, I developed a new statistical technique using multiple dimensions to prove a flaw in generated random data used in a graduate class. This was necessary because, although the random data passed all the standard statistical tests for uniform distribution, the random data was still flawed by a multi-dimensional correlation that my new technique uncovered.
This new statistical technique was implemented by taking the random data in pairs and filling a two dimensional histogram of size which is a power of two, for example scaling each number of the sequentailly generated random pair to be in the range 0..511. The number of pairs taken in this example was about 512*512/3. This histogram was then printed as an image. What was clearly visible in the image of the histogram was strong banding (rather than a uniform distribution of points).
This new technique could be implemented as an algorithm which takes the created image which is the histogram, processing it by a DFT (Discrete Fourier Transform) and looking for peaks in the spatial spectrum which are statistically significant (that is, not relatively uniform in amplitude).
As a founder of Vitesse semiconductor, in the long defunct supercomputer branch, I developed a hardware scrambler algorithm for memory bank selection to guarantee, no fixed stride would repeatedly hit the same memory bank (which would drastically limit memory speed). This technique was modified, while teaching computer science, to encrypt test questions and answers used by a testing software developed for the classes.
Whether serving as a senior scientist or special task force engineer, as a Founding Partner of MerlinCryption I have dedicated a 40-year career to mission critical projects where protecting sensitive data is paramount. The repeated need for airtight data transfer inspired me to privately develop advanced encryption that was superior to typical programs in use.
My focus in cryptography began with his master's work at CalTech in the 1960's, where I invented a new algorithm for testing probability distributions, by viewing the data in multiple dimensions. After discovering flaws in currently used random number generators and studying limitations of fixed key length encryption algorithms, I began developing a new cryptographic approach that would overcome these weaknesses.
In various projects our team needed the ability to encrypt email attachements to communicate progress in the development of our Intellectual property. I used what was learned about statistics and added additional techniques to create an effecient encryption algorithm that would use variable length keys to defeat common means of breaking cyphers. Later, after studying various cryptanalaysis techniques the algorithm was made more complex to defeat all known and many anticipated statistical and cryptanalysis techniques. The resulting encryption programs were productized with a user friendly GUI.
The new algorithm is called the Anti-Statistical Block Encryption (ASBE) algorithm.
What military wants its actual or potential foes to know their encryption algorithm? The clear answer is none. The tradeoff is there is no public peer review and published approval of the algorithm. Nevertheless the algorithm is still reviewed, but the results are classified.
In the movie "Wind Talker", which is based on a true story, the recently declassified encryption used during World War II (primarily in the Pacific theater) was the Navajo language with slang used to identify people, places and things. This was highly successful, because at the time, the Navajo language was known to almost no non Navajo person.
Since that war, computers have changed the landscape with respect to encryption, increasing the speed to both encrypt and attempts to break encryption.
Other private encryption algorithms include IBM's InfoSphere Gardium encryption algorithm, which is not described, see: http://public.dhe.ibm.com/common/ssi/ecm/en/ims14375usen/IMS14375USEN.PDF. For more details see: http://publibfp.boulder.ibm.com/epubs/pdf/decuga20.pdf. Unlike IBM's Encryption Facility for z/OS, see: http://www-03.ibm.com/systems/z/os/zos/encryption_facility/index.html which uses any of a list of well known encryption algorithms.
The Digital Rights Management (DRM) systems used to protect videos has also typically used proprietary encryption. Examples are:
Satellite TV has also typically used private encryption, but if this is broken it is quickly spread to others. See: http://en.wikipedia.org/wiki/Pirate_decryption and http://www.alibaba.com/showroom/satellite-decoder-irdeto.html.
The ASBE algorithm has been reviewed by NSA and is BIS approved for export under classification 5D992.(c), for overview on this see: http://www.bis.doc.gov/encryption/question5sub_1.htm and for details see: http://www.bis.doc.gov/policiesandregulations/ear/740.pdf, especially 740.13(e)(1).