Learn English – “I’m in transports” – Is it a correct way to say that I’m in PUBLIC transports

"I'm afraid that" is more commonly used to present a regretful report that something is the case:

I'm afraid that sales aren't as good as we'd hoped.

I'm afraid that we're going to have to Joe go (i.e. "We're going to fire Joe")

"I suspect that" on the other hand is used to postulate possible reasons why something might be the case:

I suspect that sales aren't as good as we'd hoped because Joe hasn't been performing well.

"Suspect" can also be used to postulate that an action is happening at all:

I suspect that Joe is stealing money from the till when we aren't looking.

In that is fine; in fact, it is formal rather than 'basic'.

Whereby, on the other hand, is impossible here: it means by which, and therefore claims that the fact that de-identification differs from anonymization the means by which the difference you describe comes into being: which makes no sense at all.

The problems with your sentence lie in what follows the subordinator.

1. Properly, what follows in that should be structured as a statement which tells the reader how de-identification differs from anonymization rather than merely describing the two processes and leaving it to the reader to discern how they are different. Specifically, the subject of the that clause should be de-identification.

2. Latter and former have no place in contemporary writing. Your use of them here is time-honoured, its logic is impeccable; but in a complicated sentence like this it puts a wholly unnecessary processing burden on the reader, especially when you flip the terms out of their original order. Readers are not computers, and texts are not programs: find a way of expressing your meaning that doesn't make the reader look up the refrences.

Here are couple of ways to avoid these problems:

De-identification differs from anonymization in allowing [or in that it allows] a trusted party to re-identify the data, where anonymization is supposedly irreversible.

The difference between anonymization and de-identification is that anonymization is supposed to be irreversible but de-identification allows a trusted party to re-identify the data.

These are a little bit longer than your sentence, but they're a lot easier to follow.

I have no idea what that supposedly means, so you might want to clean that up, too.