This is the 4306th most frequent German word.
erhöhten
"Erhöhten" means "increased" or "elevated."
In this sentence, 'erhöhte' is used as an adjective describing the security measures, indicating they are enhanced or at a higher level than normal.
Die Polizei hat erhöhte Sicherheitsmaßnahmen ergriffen.
The police have implemented increased security measures.
Here, 'erhöht' is used as part of the past perfect verb form 'hat sich erhöht', showing an action where something (the participant number) becomes larger or higher.
Die Anzahl der Teilnehmer hat sich durch die Werbung erhöht.
The number of participants has increased due to the advertisement.
In this example, 'erhöhten' functions again as an adjective modifying 'Anforderungen', explaining that the demands are heightened or more challenging.