Here are a few reasons why checksums change with every new request:
1. Data Changes: The primary purpose of a checksum is to detect any modifications or corruptions in the transmitted data.
If the data changes, even by a single bit, the checksum value will be different. This ensures that any unintended alterations to the data are identified, preventing the use of corrupted information.
2. Timestamps: Checksums often incorporate timestamps or sequence numbers to provide an additional layer of security. By including a time-based element, checksums can help detect replay attacks, where an attacker replays previously captured requests to gain unauthorized access.
As the timestamp changes with each new request, so does the checksum value.
3. Randomization: Some checksum algorithms introduce an element of randomization to enhance security.
By incorporating random values into the checksum calculation, it becomes harder for attackers to predict or manipulate the checksum.
This randomization contributes to the uniqueness of each checksum value generated for a request.
4. Nonce: Checksums may include a nonce (a random or unpredictable number) to further strengthen security.
A nonce helps prevent replay attacks by ensuring that each request is unique.
Since the nonce changes with every new request, the resulting checksum value also changes.
5. Algorithm Sensitivity: The specific checksum algorithm used can also contribute to the change in checksum values.
Depending on the algorithm, even minor variations in the input data can lead to significant changes in the output checksum.
This sensitivity ensures that any modifications to the original data are reflected in the checksum calculation.