# The E-Cipher Overview

by Ron Miller, April 2001

The E-cipher is a cipher algorithm with the emphasis on Efficiency so as to achieve the highest combined level of security and ease of implementation. The E-Cipher can easily be used by everyone and everywhere with nothing more than pencil and paper at one's disposal.

Previously this high ground was held by the Vigenere, then likely ‘Solitaire’, and perhaps then ‘Mirdek’, ciphers. Being a mathematician and having a detective bent, while studying at Orange Coast College and UCI,  I became very interested in mathematical puzzles and cryptography. I personally studied and researched as an enthusiast in this area over the last few decades. Then, in recent years, I went on to develop proprietary computerized cryptograph algorithms and applications. After reading ‘The Code Book’ by Simon Singh, I looked for a way to combine the best of the hand done and the very strong and successful mechanized ciphers used up to the time of computers in a way that could be implemented simply with pencil and paper, while being resistant to modern computerized cryptanalysis. From this vantage point I devised the E-Cipher.

The E-Cipher, and its derivations, are considered protected as intellectual property to the fullest extent of the copyright laws. I do hereby grant free private (non commercial) personal use of the E-Cipher to anyone using it in connection with ethical and legal activities.

## Strength of the algorithm

The E-Cipher uses (what I call) a metamorphing poly-alphabet character substitution algorithm. This has the effect that the mapping from plain text to cipher text is different for every character of a message. Testing shows that the pattern of the character mapping does not appear to repeat even after 100s of thousands of characters, and perhaps more than millions. With some ‘weak’ keys minor cyclic patterns occur on the order of one character substitution in 650, statistically speaking. This poses virtually no risk in messages not too many kilobytes long; and longer messages are not expected with a hand performed algorithm.

This algorithm does not do a simple function on the plaintext character like adding a value (regardless of how random the value is) and doing a modulo operation, such that with two encryptions using the same key you could apply a mathematical function to the two messages, eliminating the key and allowing easy attack on the messages. Therefore with E-Cipher one could reuse a key if it were absolutely necessary. Further by not being an output-feedback mode stream cipher, a mistake in encryption or decryption will not necessarily render the remaining deciphered text totally unreadable.

Ease of Use

The implementation of the algorithm is easy to learn and perform. Nothing other than some paper and a writing instrument is needed, unlike ‘Solitaire’, which requires a deck of cards. Further the key or keys are simply any set of alphabetic characters, words or phrases; and can be agreed upon or transmitted by a vast variety of means. There is no exchanging of a card deck or special key arrangements or restrictions. At most, users may need to practice printing or put tick marks or creases on their paper to help in alignment of groups of characters if their printing is insufficiently neat and consistent. Initially grid paper could be used.

The E-Cipher can be even easier, faster, and hence more efficient, with the use of a text editor (using a mono-space font). With its ability to cut, paste, shift around, and line up text, the implementation of this algorithm is very fast and easy to be accurate. You can encrypt or decrypt at a rate of more than 10 characters in three minutes, including the needed ‘key’ processing. All of this without using some incriminating application but instead a standard utility on most any computer devices. Further there is no paper trail. A file does not need to be created; just delete the context and close the app without saving anything.