The solutions without security audit after decompilation of apk include: encrypting confusing code, verifying application integrity, and detecting decompilation tools.

1. Encrypt and obfuscate code: Use the code encryption and obfuscate tool to encrypt and obfuscate application code.

2. Verification of application integrity: apk is signed to ensure integrity, and the legality of apk file is verified by using technologies such as checksum or digital signature.

3. Detect decompilation tools: Use some special tools or services to detect whether there is decompilation in the application.