Abstract: Method for fulfilling a cryptographic request requiring a value of a private key. Code portions are sent from a server to a computing unit running a web browser. The code portions are executed directly in the web browser in such a way that it automatically performs a cryptographic process including the steps of: receiving a cryptographic request requiring a value of a private key; requesting an encrypted value of the private key; receiving the encrypted value of the private key; requesting an unlocking entity; receiving the unlocking entity; decrypting the encrypted value of the private key with the unlocking entity to obtain the value of the private key; and fulfilling the cryptographic request using the obtained value of the private key.