Digital signing and verification
The qcrypto library API includes functions that provide cryptographic signing and verification primitives. Several forms are provided to give you the flexibility of using one that is best suited to your needs.
Padding
Some cryptographic primitives, such as AES ciphers in block cipher modes of operation, often require that the input data size be a multiple of the primitive's block size. Because the size of some data (e.g., plaintext) can be variable, padding can be added to meet the primitive's size requirements.