• преимуществах формата PDF в качестве документа с электронной подписью;
• платформе Java, библиотеке itextpdf и СКЗИ КриптоПро CSP, как инструментах подписи;
• о том, с какими трудностями пришлось столкнуться, о доработке itextpdf;
• привести пример кода, выполняющего несколько подписей;
• поговорить о целесообразности использования формата PDF в качестве документа с подписью.

Это короткая заметка о том, что в англоязычной сфере встречаются два термина, взаимосвязанные друг с другом, но разные по сути. Это electronic signature и digital signature. Отличия их друг от друга полезно знать хотя бы для точного понимания статей, стандартов и законов.

Мой личный небольшой опрос коллег показывает, что далеко не все вообще видят разницу.

Once the Teacher asked the Author:

Are there methods of redundancy introducing at an informational level, other than those that are studied by the theory of error-correcting codes? Emphasizing that he is talking about information redundancy, the Teacher thus made it clear that the question does not imply various ways of energy redundancy introducing, which are well studied in communication theory. After all, the noise immunity of information transmission is traditionally assessed by means of a threshold value that is calculated as the ratio of signal energy to noise energy. It is known that the methods of the theory of error-correcting codes offer an alternative solution, allowing energy saving.

After a cogitative pause, the Author answered in the affirmative, following intuition rather than rational knowledge. Upon hearing the answer, the Teacher noticed that this is a wrong conclusion and there are no such methods.

However, over time, the Author began to suspect that the immutability of the paradigm formulated above could be questioned.

In this note, we discuss the Instant Digital Signature (IDS) mode, which was announced earlier. While the main content of the IDS mode was already disclosed in a previous publication, we believe that additional specifications will improve understanding.