Fetish-Numbers - Marie de Sade, Dr. Olaf Hoffmann (the beach read TXT) 📗

of syllables are composed of letters, glyphs and general signs. Therefore an alphabet typically needs even less symbols than a syllabar. Different languages can share the same alphabet, but sometimes they introduce special characters, such as umlauts in the German language. This increases the number of characters, which can even exceed the number of characters of a syllabar of a single language with syllabic writing.

During digitisation, all characters are more or less numbered with encodings like UTF-8 (Unicode). This is done accordingly for syllabars, character collections of logographic writings as well as picture writings, with the problems associated with the latter of having to extend such encodings when new characters appear, which happens much less often with letter writings.
In blocks of writing systems, where the probability of additions is high, gaps are generously left in the numbering, which can be used later if necessary, filled with new glyphs.

While a language is an open system in which new words are constantly being created and their meanings can be defined, a work, a book is to be regarded as a closed system with a finite vocabulary. In such closed systems it can be more efficient to simply number all words, analogous to UTF-8 to encode in a resource-saving way. Statistical analyses show that even extensive collected works of all known authors per language with an encoding of less than two bytes per word on average would be sufficient, if the system of UTF-8 or UTF-16 were applied in a similar way as for characters. This is because the information content at word level in monolingual books is typically between 8 and 13 Shannon, depending on the size and author, so even in trilingual books 16 Shannon is not reached, corresponding to an average of two bytes per word.
A serious drawback is, of course, that with individual encoding, one encoding table per book would have to be added in order to decode the content again, which can make this approach inefficient.
Since the vocabulary of a language without consideration of composites and similar constructions again only contains a few million words as maximum value, even a standardised coding of words could be useful to achieve an optimal data compression.

The matter is different, if information is not supposed to be generally readable at all, or if a finite vocabulary has to be exchanged only once in a limited field or due to a standard similar to UTF-8, messages can be decoded afterwards without a coding table.

This results in an approach to cryptology, in which coding or encryption on the one hand is separated from decoding or decryption on the other. With knowledge of the language used, however, it is possible to deduce often used words via statistical analyses. These are usually not the content information of a text. Nevertheless, this is an indication that this coding alone is not sufficient to encrypt a text securely.

Cryptology

Cryptology can be divided into two parts: cryptography and cryptanalysis. In general, cryptology is about coding messages, information. The term 'crypto', therefore hidden, covert, indicates that coding is particularly concerned with the fact that the information in question is by no means to be coded in a generally accessible, comprehensible, standardised way, especially in the optimum case it is coded by the sender in such a way that only certain recipients can extract and decode this information. Senders therefore encrypt their messages in a suitable way, keys for decrypting these messages are only available to selected, explicitly authorised persons. This is cryptography.

With cryptanalysis, on the other hand, the concern is to find a way for an unauthorised person to decode encrypted information.
There have always been secrets that insiders want to exchange among themselves, but at the same time hide from unauthorised persons. Some unauthorised persons also have a massive interest in obtaining knowledge of this information, especially when it involves actions against themselves.

Wars, economic trade, and generally competitive situations between groups offer many opportunities for the application of cryptography. Common to most of these occasions is that the necessity to keep a message secret is limited in time, because the occasion of the communication or the relevance of a message is limited in time, a later decryption can no longer harm the project. Sufficient for an appropriate encryption is that unauthorised persons need longer to obtain a key than the actual message is relevant for the project.
In addition, there can also be sensitive information for an unlimited period of time, which should never be decoded by unauthorised persons. Such information therefore requires an even more sophisticated method of coding, which must be considered secure for an unlimited period of time.

Conversely, a cryptanalyst tries to decode messages as quickly as possible while the information they contain is still relevant. If a found key virtually fits into the hole, the secret is exposed, naked, willing, available, ready to be used at will. This making of foreign messages compliant can become a key experience, through which after the intoxication of meticulous search, the short climax of success, a focus in the form of a development of a fetish can follow. What satisfies, occupies, irritates as foreplay, stimulates the analyst's psyche.

In first, simple cryptographic attempts, only all available characters or syllables were numbered consecutively or reversibly permuted. Sender and receiver have the same list, which again uniquely assigns characters or syllables to the numbers, or inverts the permutation. This encryption is therefore symmetrical, both use the same table. A naive unauthorised person cannot do anything with an intercepted or copied message if this person cannot get to that list by other means.

A simple solution to the decoding problem with these classic procedures is therefore always to obtain the key to decode the exchanged information, optionally to smuggle in fake messages to confuse the opponent, and to break up cooperation by manipulation.
In addition to intercepting a key, statistical analyses and the comparison of different messages can also be used to advise a key.
On the cryptographic side, this results in the task of qualified authentication of the sender.

In such analyses, it is often known in which language and in which writing system the unencrypted messages examined were written. The occurrences of letters or characters in a larger text, for example, are quite characteristic for the respective language; occurrence distributions for German and English differ significantly.

If all characters of a writing system are simply numbered according to a separate list during encryption, an occurrence analysis of the numbers used provides a probable assignment of these numbers to characters, this means a partial key. In a partially decoded text, words will appear in which perhaps only one or two characters are not decoded. In some cases, however, there may still be a unique assignment if the language used is known, so that further number-character assignments are decrypted – the procedure is continued until a complete list is available, so that all messages can be decrypted immediately that have been encrypted with the same method.
In this sense successful unauthorised persons can decrypt all messages at the same speed as authorised recipients.

In a next step of cryptographic strategy, keys are therefore simply made more complex. A secure procedure consists, for example, in the fact that authorised senders and receivers of a digital message have the same sufficiently long sequence of random bits, which only have to be hidden from unauthorised persons. This random pattern is added to a message bit by bit before it is sent. An authorised recipient again adds the same bit sequence to the transmitted message on receipt and has thus decoded it.

The noise of the random pattern does not allow statistical analysis. The only chance for decoding by unauthorised, interested persons is therefore to obtain the bit pattern or to access messages before encryption or after decryption.

The situation can already become more complicated if the same bit pattern is used for several different messages. Here, depending on the complexity of the message pattern, it can no longer be mathematically-statistically excluded that parts of the bit pattern can be guessed. Pattern recognition may therefore be possible. For example, if two messages have longer sequences of the same cipher, the bit pattern of this encryption will shine through here after encryption, and can be used for partial decoding in a third message. Data compression before encryption avoids such long sequences, but such files always start with the same known character sequence.

The sender and receiver are therefore on the safe side if they use a different random bit pattern for each message. Of course, secure exchange and safe storage and removal of this pattern is problematic, so that it does not become accessible to unauthorised persons who have already intercepted a message encrypted with it.

Thus, the search was on for ways in which transmitters and receivers do not have to exchange their keys personally on a secure channel before communicating.
For this purpose, as well as for messages that are only secret for a limited period of time, the method of asymmetric keys has been established, which are usually much shorter than most messages for practical reasons. A potential recipient of a message generates a key pair from a public and a private key. A public key is published for each interested communication partner. A sender can use this key to encrypt messages that are sent to the producer of the key pair. Only one recipient in turn has the second, private key, with which it is possible to decrypt messages again.

The trick of this asymmetry is that it is difficult to calculate the private key using the public key on classical computers. For example, if such a calculation takes at least ten years, such a key can be used to securely exchange information that is no longer relevant ten years after it was sent. Such an estimate must take account of the fact that computers available in the ten years will become more powerful.

Now it is relatively easy to generate keys which will not be cracked with today's computers even in millions of years. However, quantum bits, quantum computers have been in development for some time. Due to special properties of quantum bits, special calculations and analyses can be carried out significantly faster than with classical computers, the mathematical methods for cracking keys are completely different. What would perhaps take a million years with a classical computer, takes only a few hours with a quantum computer, as it may exist in ten or twenty years.
This development of quantum computers therefore makes it necessary to use other encryption procedures, to develop them or to supplement existing ones, so that methods, procedures of computing with quantum bits no longer offer any advantage in decryption.

The antagonist of quantum cryptanalysis is again quantum cryptography. Its core idea is to use a secure channel or secure methods for data transmissions where copying, manipulating data is not possible or at least automatically destroys messages. Due to the special properties of entangled quantum particles, it is possible to generate the same random bit pattern at the sender and receiver – and only at the moment when the sender or receiver measures the bit pattern, after which they agree on a public channel, which of these they can use as a key, then exchange encrypted messages with it.
Someone who wants to copy entangled particles for himself on the way would in turn carry out a measurement, thus changing the bit pattern for the receiver; transmitter as well as receiver notice a falsification when discussing the key and discard the bit pattern, whereby it need not be clear whether a disturbance is due to an unauthorised