Q: What is Privacy Captcha?
A: Publishing private information, such as e-mail addresses, phone numbers, postal addresses and so on, is quite common these days. Some big Internet companies automatically process your data to gather information about you. This may even include data you send to a specific person, e.g., in a private message on Facebook, WhatsApp or within an e-mail! They may use the gained knowledge to send you advertisements, to sell information about you (or your friends) to other companies or even worse things we cannot currently imagine. While it is always the best idea to boycott such services, sometimes this is not feasible. In this case, Privacy Captcha can protect your data by encoding it into an image. And even better, we distort the image so that even advanced picture analyzers cannot automatically extract your information. Of course we can not promise 100% security, but analyzers should have a hard time to get your data out of a Privacy Captcha.
Q: Is Privacy Captcha suitable for daily communication?
In principle, you could use Privacy Captcha in this way. However, we recommend to switch to a communication service that supports end-to-end encryption and cares about privacy as early as you can. For example, we recommend Signal
(widespread, very convinient) or Riot
(less widespread, superior data privacy protection) as an alternative to WhatsApp. A convenient and open chat network is Jabber/XMPP (learn more
), which can be encrypted using OMEMO. However, you can use Privacy Captcha to establish the first contact, e.g. via Facebook. See the following exmaple:
Q: How about using Privacy Captcha on websites for spam protection?
In theory, Privacy Captcha would be perfect for that. You could encode your e-mail address as a Privacy Captcha and thereby protect it against crawlers. However, be aware that persons with visual impairments have problems with Privacy Captchas. They use software that transforms text into audio, but images, such as Privacy Captchas, cannot be read by such software. Be aware that in cases where providing contact/ownership or other information is required by law, such as the "Impressum"
or imprint laws in German-speaking countries, you might run into legal problems if you only provide these as a Privacy Captcha. Please check the laws that apply to you.
Q: Can Privacy Captcha protect me against the NSA?
A: The NSA is in the media all the time. Privacy Captcha is not designed to protect you against the NSA but against large Internet companies that process and use your data. Please use trustworthy software with proper end-to-end encryption to protect yourself against mass surveillance.
Q: Captchas are broken in general. Aren't they?
A: Some people say so. However, nobody has been able to prove that this is the case for Privacy Captcha. Thus, geeks and hackers: here is our challenge for you! Try to show us that Privacy Captcha is broken. Send us some code that can read Privacy Captchas in practice. For example: Show us that your program can read the whole Digitalcourage phone number that is part of the default textbox content from a majority of the randomly generated Captchas. Your reward: A free organic-cotton Digitalcourage T-shirt and a huge, huge thank you. Have fun :-)
Q: Who operates Privacy Captcha?
Privacy Captcha is a project of Digitalcourage e.V.
, a nonprofit organization in Bielefeld, Germany focusing on civil rights, data privacy protection and a world worth living in in the digital age.
Q: Do you store any data that has been typed into the textbox?
A: We never store the plain text. The generated image is stored for 60 minutes and then deleted.
Q: Do you do any tracking?
A: According to our philosophy, there is no tracking on our websites at all. We neither store your IP address nor something else. Our servers are hosted in Germany.
Q: How does the captcha algorithm work?
We use the captcha implementation of HKCaptcha
. The algorithm has been implemented with captcha-defeating research in mind. See the website for more information.
Q: How can I contact you?
Send an e-mail to the following address. Generated by Privacy Captcha ;-)