You can reach this dialog via the menu entry Digital Signatures/PKI \ Signature Demonstration (Signature Generation).
This dialog allows to execute all steps of the RSA signature process, and therefore it will show transparently the details of the RSA signature generation.
As to visualize the actions of the signature generation, the flowchart of this process has been implemented into a dialog. To understand it, you can try out and combine the operations: hashing, asymmetric encryption and the use of a certificate.
Several coloured symbols are used for buttons:
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Symbol for preparations (e.g. select a hash function). |
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Symbol for manual data input (e.g. key generation). |
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General symbol for data (e.g. hash value). |
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Symbol for stored data (here certificate). |
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Processing symbol (here: signature generation). |
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Process end symbol (e.g. store signature). |
The colors of the symbols illustrate the actual state of the individual process step within the flowchart:
red | Operation to handle (preparation / input / process). |
green | Finished operation (preparation / input / process). |
blue | Available data (display and further process steps are possible). |
grey | Inactive (missing data or not yet executed preliminary processes). |
Dependencies between symbols are visualized by arrows. Active buttons (red / green / blue) can be multiple times selected and/or selected in random order. Grey buttons are inactive and can't be selected. A process button will be activated if all preliminary linked operations are executed, and so the required input data is available (all preliminary buttons are coloured blue).
On each symbol on lower left corner there are additional icons placed. Those icons symbolise the type of the operation / data element:
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Input file for the digital signature. |
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Information about the selected hash function. |
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Hash value of the input file. |
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Secret RSA key for hash value decryption (signing process). |
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RSA-encrypted hash value. |
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Stored certificate. |
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Complete RSA signature, on this header, the input file will be attached later. |
The view of this flow chart is separated into five rows:
The first row contain all operations, which are prerequisites for the signature generation.
The second row shows the input data of the two main signature operations.
The third row shows the signature operations of hashing and RSA decryption.
In the fourth row, you can display the output of the above operations.
Using the buttons of the fifth row, you may cancel the dialog or store the digitally signed document, before the dialog is closed.
If you click on the data symbols (row two and four), then the selected information will be show into the text field below the flow chart.