The central system for server e-signature SI-CeS allows the creation of an electronic signature with the private keys of the digital certificate holder, which are securely stored in the central system. The service is flexible and supports a variety of options for the implementation of e-signature: in enables the creation of an e-signature in accordance with different standards or formats (binary, XML, PDF, CMS); the creation of an e-signature at different levels will be supported (qualified e-signature, advanced e-signature, certified by a qualified certificate); the user has several options for authentication in the creation of an e-signature, according to the required level of the e-signature and the authentication mechanisms supported by the central authentication system Si-CAS. The service enables a secure e-signature without the user having to install any signature components. The use of e-signature is supported in all user environments, both fixed and mobile.