Create a digital signature for Android and an android Digital Signature

Create a digital signature for Android and an android Digital Signature

To create an Android Application, you need to use the keytool in jdk, as shown below:

First, cmd
Enter the command: keytool-genkey-v-keystore gkhapp. keystore-alias gkhapp-keyalg RSA-validity 1000

Note:-keystore gkhapp. keystore indicates the generated certificate. You can add the path (in the user's main directory by default).-aliasGkhappIndicates that the certificate alias is gkhapp;-keyalg RSA indicates the RSA algorithm used;-validity 1000 indicates that the certificate is valid for 1000 days. (The validity period must be greater than 1 year)

The file will be found in the user's home directory

When installing Android software, the system prompts that there is no digital signature certificate. How can this problem be solved?

This is a software issue. During Android development, you need a certificate and password prepared by a developer. The certificate and password must be packaged into your installer, during your installation, the background of the Android mobile phone needs to check whether your software has a certificate. If you do not have a certificate, you can check the unknown items. The certificate is equivalent to an ID card, you don't have a certificate. We recommend that you perform another test !!!
 
How to create a digital signature

Document Security Level

Macro virus is the biggest security risk for Word documents. In order to prevent macro virus, Word sets up the concept of security level. You can set the security level on the "Security Level" tab of "Tools> Options>" security "tab> macro security". The security level is divided into three levels: High, Medium, and low. The high level will only run the macros of reliable sources, and the other macros will be canceled; the middle level will not open a macro, you will see a warning, let you choose whether to enable; macro Protection is not implemented at a low level. When you select a high level, Macros in installed templates and add-ons (including the wizard) may be disabled. You only need to click the "reliable sources" tab in "Tools> Options> Security> macro security", and then click the "trust all installed add-ons and templates" check box, so that the installed macros are not disabled. Note: All templates, add-ons, and macros with Microsoft Office XP are digitally signed by Microsoft. Once an installation in these installed files is added to your reliable source list, subsequent interactions with these files will no longer generate messages.

Digital Certificate Protection

The sources of many documents are unknown, so security cannot be guaranteed. Office can use digital certificates to confirm the reliability of the source. Use the digital certificate to sign a file or macro. Generally, digital certificates are obtained from commercial Certificate Authorities and internal security administrators or information technology professionals. Ordinary users can use the selfcert.exetool to manually create digital signatures (the digital certificate created by selfcert.exe is not issued by the formal certificate authority, and the macro scheme for adding signatures using this certificate will be considered as self-signed, in this way, other users may not be able to run self-signed macros ). Using a digital certificate to sign a macro is simple: open the file containing the macro file to be signed, in "Tools> macro> Visual Basic Editor> Project Resource Manager, select the scheme to be signed. Click the "Tools> digital signature" command.

Tip:

1. You must sign the macro after the macro test is confirmed. Because the code of the signed macro project has been changed, its digital signature will be deleted. If it is a self-signed certificate, the macro case will be automatically re-signed every time it is saved.

2. If you want to prevent the signature from being invalid due to accidental modification of the macro case, please lock the macro case before issuing. Your digital signature can only indicate that you have ensured the security of the solution, and it cannot prove that you have compiled the solution. Therefore, locking the macro scheme does not prevent other users from using another signature to replace your digital signature.

3. if you have created an add-on that can add code to the macro scheme, the Code should determine the following: if the scheme has been digitally signed, before running, whether to notify the user of the result of modifying the signature scheme.

There are two types of file passwords in Word: Modify the permission password and open the permission password. Open the permission password to convert the Word document to a read-only file. If the document is opened and changed, you can only save the document as another file name. You can modify and save the permission password at will. Specific setting method: open the file and set the password on the "Tools> Options> Security" tab.

Tip: to create a long password, click "advanced" and select the RC4 encryption type.

File Password settings

There are two types of file passwords in Word: Modify the permission password and open the permission password. Open the permission password to convert the Word document to a read-only file. If the document is opened and changed, you can only save the document as another file name. You can modify and save the permission password at will. Specific setting method: open the file and set the password on the "Tools> Options> Security" tab.

Tip: to create a long password, click "advanced" and select the RC4 encryption type.

Prevent users from modifying forms

Some documents need to protect the form so that others can only enter information in the specified area. Therefore, Office provides form protection. When the form protection function is used, any information in the form field will be reset. Specific Method: "Tools → protect documents → forms ". If you want to specify a password for the form, so that the rest of the text is...>