Договор требует сохранить конфиденциальность исходного текста.

Because договор is the subject of the sentence: it is the thing that requires something.

• договор = contract, agreement
• требует = requires

So Договор требует ... means The contract requires ...

Russian subjects are normally in the nominative case.

Требует is the 3rd person singular present tense form of требовать.

That matches договор, which is:

• singular
• masculine
• treated as it in English

So:

• я требую = I require
• ты требуешь = you require
• он / она / оно требует = he / she / it requires

Here, договор требует literally means the contract requires.

Because Russian often uses требовать + infinitive to express that something requires an action.

So the structure is:

• требует сохранить = requires to preserve / requires one to preserve

This is similar to English patterns like:

• The contract requires keeping confidentiality
• The contract requires you to preserve confidentiality

Russian does not need to say кого is doing the action here. The sentence just states that the contract requires that this action be done.

This is a question of aspect.

• сохранить = perfective
• сохранять = imperfective

The perfective сохранить presents the action as a whole result: to preserve / to keep intact / to ensure is maintained.

In this sentence, the idea is not about an ongoing process in general, but about achieving the required result: the confidentiality must be preserved. That is why сохранить sounds natural here.

Very roughly:

• сохранять = to be preserving, to preserve habitually or in process
• сохранить = to preserve successfully, to keep something intact

Конфиденциальность is the direct object of сохранить, so it is in the accusative case.

However, for many feminine nouns ending in -ость, the accusative singular looks exactly the same as the nominative singular.

So:

• nominative: конфиденциальность
• accusative: конфиденциальность

That is why the form does not visibly change.

Because the sentence is talking about the state or principle of confidentiality, not describing a noun with an adjective.

Compare:

• конфиденциальность текста = the confidentiality of the text
• конфиденциальный текст = a confidential text

These are related but not identical.

In your sentence, the idea is that the contract requires preserving confidentiality as a concept or condition.

Because they depend on конфиденциальность.

The phrase means:

• конфиденциальность чего?
• the confidentiality of what?
• исходного текста

So текста is genitive singular of текст, and исходного agrees with текста in:

• case: genitive
• number: singular
• gender: masculine

This is a very common Russian pattern:

• часть книги = part of the book
• начало фильма = beginning of the film
• конфиденциальность текста = confidentiality of the text

Исходный текст usually means source text or original text, depending on context.

Possible translations include:

• source text — especially in translation contexts
• original text — in a more general context

The adjective исходный often has the sense of:

• original
• initial
• starting
• source

So конфиденциальность исходного текста means the confidentiality of the original/source text.

Yes. Russian word order is flexible because case endings show grammatical relationships.

The neutral order here is:

• Договор требует сохранить конфиденциальность исходного текста.

But other orders are possible for emphasis, for example:

• Конфиденциальность исходного текста договор требует сохранить.

That version puts focus on конфиденциальность исходного текста.

Still, the original sentence is the most straightforward and natural for a neutral statement.

Russian has no articles.

So договор can mean:

• a contract
• the contract

And исходного текста can mean:

• of a source text
• of the source text
• of the original text

Which one sounds right depends on context. English must choose an article, but Russian does not.

Yes, it sounds fairly formal and fits legal, official, or written style very well.

That makes sense because the subject is договор. Legal and administrative Russian often uses structures like:

• договор требует
• закон требует
• инструкция требует

In casual speech, a person might phrase things differently, but in documents this style is very natural.

Not in natural English. That would sound ungrammatical.

A better English rendering would be something like:

• The contract requires the confidentiality of the source text to be preserved.
• The contract requires preserving the confidentiality of the source text.
• The contract requires that the confidentiality of the original text be maintained.

So the Russian structure is normal, but English usually needs a different wording.

Yes. Russian leaves it unspecified here.

The sentence does not say exactly who must preserve the confidentiality. It simply states that the contract requires this action.

Depending on context, the implied doer could be:

• one of the parties
• the translator
• the recipient
• anyone bound by the contract

This kind of omission is common in Russian, especially in formal style.