Domain owner and responsible for content
according to § 55 RStV for

Pe­ter Jockisch
Habs­bur­ger­stra­ße 11
D-79104 Frei­burg i.Br.

Telephone landline: +49 (07 61) 55 14 68


According to legal requirements for imprints, a phone number must be stated; however,
please, read the notes on communication.

The OpenPGP-key is available in the imprint section of my personal site,
There are also biographical notes available.

RSS-Ikone-Illustration RSS News ticker to  •  RSS introduction article

Prefered Communication Medium: Cryptographically signed E-Mail

Currently, the effective protection that can be achieved with publicly available cryptographic technology is highly questionable. Advanced computer technology is likely to be kept out of the public domain in order to keep the intelligence services of the rulers at the forefront of com­put­ing power. In addition, software and hardware back­doors probably exist. Officially recommended stand­ard­ized encryption methods may have inherent mathematical weaknesses: Why should the intelligence services of the Wes­tern and Eastern hemispheres recommend and give away self-developed secure algorithms whose use would make their central work, interception and industrial es­pio­nage, impossible?

The higher-ranking organizations of those families who stand above the law most probably have an incomparably strong calculating power, which normal users have little to oppose. However, some of the potential attackers under the law can be fended off. The communication security can be increased at least within a certain framework, by consistent use of cryptographic signing.

All my e-mails are always signed cryptographically, with PGP/MIME or a separate signature. I never send un­signed e-mails without any exception. Signatures need to be verified, for example with GnuPG GNU Privacy Guard,, MS Windows version: I only use the key listed in the imprint. is the only official source for my key.

Signature verification with OpenPGP and GnuPG

To view a name and a cryptographical checksum, is not sufficient. For the authen­ti­ca­tion, the signature must be veri­fied. After the initial activation, modern e-mail agents fully and au­to­mat­ically verify in the background.

For the qualified electronic signature, most often, only hardware-based (chipcard) class-3-certificates, certified by legally recognized CAs are accepted by law. However, the re­quired hardware and software infrastructure (avail­able card readers, supported operating sys­tem, e-mail agent, software) is throughout of proprietary nature. This means not check­a­ble and visible and thus, risky under security aspects. If attached to your email, I maybe will use such public X.509- or OpenPGP cer­tifi­cates with my MUA – However, I myself do not sign with such cer­tifi­cates

Cryptographical checksums as alternative proof of authenticity

Some recipients are not familiar with practical encryption and signing, or they have no pos­si­bil­i­ty to use it in their country. In these cases, in addition to the signed e-mail, I write the mes­sage seperately in a “.txt” or “.pdf” file and publicize its checksum in the checksum blog section on, combined with the date of dispatch, sending time and initials indicating the document.

Checksums for files can be created with a single right mouse click, for example with Free Software like Cyohash or Jacksum. More information about the application pos­sibil­ities can be found in the introductory article “Practical application of cryptographic checksums”.

For verification, the checksum of the attached “.txt” or “.pdf” file must first be formed. You can then check the checksum blog area of to see whether there is an entry with the corresponding checksum for the e-mail date in question. Checksums of my e-mails are published there and only there, nowhere else:

My e-mail texts do not contain any data on the checksum. That would be completely sense­lessly. Everyone could write an arbitrary file and subsequently copy a checksum of the blog sec­tion into the e-mail text.

SSL/TLS certified site sections will follow.

No Telephony, no Mobile Telephony, no Fax

Principally, on a business level, I do not communicate by telephone which is unsuitable for proof of identity. With regard to the authenticity of spoken language, it is sug­gested to every­one, to inform about “Adobe Voco”, for ex­am­ple by a Google search for “Adobe Voco”.

Telephone information is principally not given. I do not own a mo­bile phone and no fax machine and I deny re­spec­tive contracts or offers.

Due to telephony being unsuitable for proof of identity and the high risk of im­per­so­na­tion, I only conduct phone calls with immediate family, using landline network only. I prin­ci­pal­ly do not use mobile telephony, SMS or fax.

In many fields (energy production, communication, health etc.), there are beneficial free technologies, methods and procedures, which are not permitted, which are to the present day held blocked. However, future generations will be able to use these technologies and methods.

The currently allowed telephone mobile communication technologies have inherently numerous criti­cal aspects, which are documented in numerous films and articles, amongst oth­ers in the following lecture (held in German) as well as in a documentary:

Further information are also available on and, among others in the “Mo­bil­funk­bro­schü­re” of the comprising information site Do­ku­men­te → Do­ku­men­ten­ar­chiv (PDF‘s+Doc‘s).

The national and international websites of the link lists there, “Links” and “Links zu”, as well as numerous other websites, also including the column “Cell Phone Dangers” of the news portal, contain detailed in­for­ma­tion on the subject.

Critical illustrations on the cell phone technology which is permitted by the rulers are avail­a­ble at dees​il​lus​tra​tion.​com .

I do not engage in discussions, neither on the telephone nor on site. Who has a say may do that in written form, pref­er­ably via e-mail. Unfortunately, an answer guarantee can­not be given.

No representatives, no employees

I neither have representatives, nor assistants nor em­ployees who speak for me. I do not work with marketing or advertising space agencies. This will not change in the fu­ture. I do not offer any job.

I don't have any representatives and don't work with mar­ket­ing or advertising space agencies.

I have no jobs to offer, applications of any kind are un­wan­ted.

No Advertsising E-mails or Letters, no Newsletters, no Product Advertising

Non of my websites sends advertising e-mails or news­let­ters. I principally do not use newsletters, instead I use con­sist­ent­ly RSS news tickers which have numerous ad­van­tages over e-mail newsletters. Introductory article: „Keep up with the News with RSS Feed Readers.“

I principally do not write readers' letters, and do not send any advertising e-mails, ad­ver­tis­ing letters, or news let­ters.

All information are offered exclusively “passively” on my own official websites. Current news and notifications can be read in news sections and can be obtained via RSS news tickers publicized on my official websites

All websites recommended by me are exclusively listed on my own websites. I do not practise banner exchange.

I neither use Facebook nor Twitter nor MySpace, no eBay, no PayPal, or any other similar services.

General remarks on precautionary measures in e-mail communication: Fraudsters, e-mail spam senders (WP article “Spamming”) and discrediters/eputation-damaging persons often use real e-mail ad­dresses from the Internet to underpin their credibility. The sender name and sender address of an e-mail can easily be forged. In addition, the utmost caution is required when attachments such as .zip files are attached to alleged invoices, credits, declarations of love, faxes, etc., which are intended to lead to ill-considered action and opening of the attachment as a result of emotional turmoil. Forwarding a suspicious email to a third party for analysis is also risky, as it could put you on the list (blacklists) of senders of fraudulent and spam emails fully automatically (via email delivery system analysis procedures) and discredit your own email ad­dress. In general, every step should be carefully planned in such cases, as otherwise you run the risk due to ill-considered reactions that those affected by the identity theft (WP article “identity theft”) could also take legal ac­tion against you because of damage to their reputation.

I do not practise banner exchange. “Business propposals” of any kind are unwanted.

No Collection of Donations, no Appeals for Donations

I don't collect donations: I don't write any donation emails and I don't call for such actions. I do not have a donation function for myself or for my internet pages. I do not send any advertising material for third parties, nor do I send any donation-call e-mails or letters for third parties.

This information is given in order to exclude possible free riders.

September 17, 2021

Copyright and translation rights 2011–2021 by Peter Jockisch,

All brand names, trademarks and work titles listed are the property of their respective owners.

The graphics used come partly from external sources. Their authors are known by name and have expressly agreed to a free usage, per clear license. The concerned images contain in the “Alt” resp. in the “Title” element an image source reference that appears when you hover over
with the mouse pointer.

A majority of the images come from the “Oxy­gen” and from the “Cry­stal Pro­ject” and is avail­a­ble at “Wi­ki­me­dia Com­mons”. Overviews:
“Ca­te­go­ry:Cry­stal Pro­ject” • “Ca­te­go­ry:KDE icons” • “Tan­go icons” • “Ca­te­go­ry:GNOME Desk­top icons” • “Ca­te­go­ry:Icons”

Imprint  •  Privacy Statement