German term (edited): Informationen sind der Rettungsschirm der Demokratie

Hard to know without context, but if this is a version of the quotation by Thomas Jefferson, it could work.

Information is the currency of democracy (Spurious ...
Thomas Jefferson's Monticello
https://www.monticello.org › research-education › inf...
Quotation: "Information is the currency of democracy." Variations: "Information is the currency of democracies." Sources consulted: Searching on the phrase ...

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Note added at 21 mins (2024-02-13 10:51:43 GMT)
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Information is the currency of democracy: a New Zealand ...
Emerald Insight
https://www.emerald.com › ... › Library Management
by P Carnaby · 2003 · Cited by 10 — “Information is the currency of democracy”, attributed to Thomas K. Jefferson, the draughtsman of the 1776 US Declaration of Independence is a ...

As in the examples below

AllegroTrans’s answer is more idiomatic, but this might be an interesting alternative if the Jefferson quotation is unintended and you want to preserve more of the impressions of the original German idiom.

German term (edited): Informationen sind der Rettungsschirm der Demokratie

Democracy requires [relies/rests on] (well-)informed decisions

Ich würde mich hier ganz vom "Rettungsschirm" lösen.

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Note added at 2 hrs (2024-02-13 13:09:28 GMT)
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Und Björns im Diskussionsbereich geäußertes Argument zu den "Informationen" ist nicht von der Hand zu weisen.

German term (edited): Informationen sind der Rettungsschirm der Demokratie.

Ok, here I go: An umbrella is symbol of shelter and protection.
The umbrella usually symbolizes the canopy of the heavens, shelter, and protection. The parasol is a symbol of the sun, and an umbrella is a symbol of the shade. It is often an emblem of power and dignity.

I prefer a more literal translation, adhering to the German idiom (if this works for native speakers).

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Note added at 3 Stunden (2024-02-13 14:14:39 GMT)
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https://edition.cnn.com/2014/09/30/world/asia/objects-hong-k...

The problem with the source slogan is, it is already biased in the sense, that it is written from a position, that claims superiority over other forms of political systems, yet tries to convey a notion of objectivity at the same time – hence we are dealing with a piece of propaganda so to speak.
To gain an more intrinsic understanding of my proposition I would like you to read the following quote also used in the bbc documentary “Manufacturing Consent: Noam Chomsky and the media”
“Modern industrial civilization has developed within a certain system of convenient myths. The driving force of modern industrial civilization has been individual material gain, which is accepted as legitimate, even praiseworthy, on the grounds that private vices yield public benefits in the classic formulation.

Now, it's long been understood very well that a society that is based on this principle will destroy itself in time. It can only persist with whatever suffering and injustice it entails as long as it's possible to pretend that the destructive forces that humans create are limited: that the world is an infinite resource, and that the world is an infinite garbage-can. At this stage of history, either one of two things is possible: either the general population will take control of its own destiny and will concern itself with community-interests, guided by values of solidarity and sympathy and concern for others; or, alternatively, there will be no destiny for anyone to control.

As long as some specialized class is in a position of authority, it is going to set policy in the special interests that it serves.But the conditions of survival, let alone justice, require rational social planning in the interests of the community as a whole and, by now, that means the global community. The question is whether privileged elites should dominate mass-communication, and should use this power as they tell us they must, namely, to impose necessary illusions, manipulate and deceive the stupid majority, and remove them from the public arena. The question, in brief, is whether democracy and freedom are values to be preserved or threats to be avoided. In this possibly terminal phase of human existence, democracy and freedom are more than values to be treasured, they may well be essential to survival.”
https://www.goodreads.com/quotes/459969-modern-industrial-ci...
Since at this stage of human development we are always dealing with works of “Public Relations” when it comes to politics, objective truths or facts not only have become a rare sight, but also they are being actively manipulated or excluded from media presentations in order to serve the prevailing “special interests”. One example being the omission of ethnic, religious and national origins of perpetrators in news articles in an attempt to prevent racism.
Also, without prejudice, even when we deal with information at its most basic, we are always dealing with belief systems in a society on the receiving end. Meaning:
“However, one can fact-check news, but not beliefs,[11] and studies show that fact-checking can backfire.” https://en.wikipedia.org/wiki/Misinformation
Hence, objectively, when looking at the given source text, we are presented with a semiotic piece of propaganda protecting and defending the interests and agenda of those in power by trying to induce fear (Rettungsschirm) on the receptive party´s end and make it follow their narrative.
The existing political scenario in a rather very anti-democratic fashion (hypothetically: e.g. what if the majority really wanted a dictatorship?) resembles the functioning of a firewall: “ Die Aufgabe einer Firewall ist so ähnlich wie die einer Brandschutzmauer bei Häusern, deshalb heißt sie wohl auch so. Die Firewall besteht aus Hard- und Software, die den Datenfluss zwischen dem internen Netzwerk und dem externen Netzwerk kontrolliert. Alle Daten, die das Netz verlassen werden ebenso überprüft, wie die, die hinein wollen.“
https://www.bsi.bund.de/DE/Themen/Verbraucherinnen-und-Verbr...
Though at first the slogan „Information is the firewall of democracy” seems contradictory, at a second glance it illustrates the use of (certain) information as information warfare protecting an inner core (here the current, existing version (I will not go so far as to call it the myth of) democracy).
It kind of works on two levels here.

Disclaimer due to the sensitive nature of the topic: As a liberal thinker I hereby deny any involvement or engagement in mind or deed with political, religious or social organs aiming at establishing dictatorships of any kind. I have tried to examine and illustrate the situation in an objective manner. I am aware though that objectivity cannot satisfy everybody´s views and wish people to peacefully accept and respect this fact.

German term (edited): Rettungsschirm der Demokratie

"Backstop" in the sense - much used in relation to Brexit & the Northern Ireland issue - of something that kicks in when everything else goes wrong, in order to prevent disaster. A bit like an emergency parachute does.

https://dictionary.cambridge.org/dictionary/english/backstop

A long time ago I would have agreed with that thesis but certainly not today.

Anyway, I think this conveys the concept adequately:

"Our democracy’s insurance policy is supposed to be the resilience of our democratic institutions, and there is ample evidence that they are now being transformed from obstacles that could contain Trump’s impulses into vehicles to punish his opponents."
https://www.theatlantic.com/ideas/archive/2020/06/american-o...