Distributed streaming platforms such as Pravega, Kafka, and Pulsar are widely used for high-throughput, low-latency data processing. As these platforms increasingly handle sensitive data, ensuring data confidentiality and integrity becomes critical. Trusted Execution Environments (TEEs) offer secure computations that can be used on client-side processing, but their impact on performance must be carefully assessed. This study evaluates the write latency of Pravega clients running in TEEs compared to those in standard (non-secured) environments. We found that under typical workloads, TEE-based clients experience approximately 50% higher latency due to the overhead of secure executions. However, when data rates exceed 976 MB/s, the Pravega broker reaches its throughput limit, causing latency to spike for standard clients. In contrast, TEE-based clients exhibit more stable latency under these high-throughput conditions. These findings can be helpful for data architects, as systems highlight a trade-off: while latency may increase, the impact could be acceptable in certain scenarios given the enhanced security benefits.