[Backend] Conduct security audit on Transaction Signer

[emdevelopa]

Description
This task involves system optimization for the Transaction Signer module.
The goal is to conduct security audit on Transaction Signer to enhance the platform's robustness, security, and developer experience.

Requirements and context

• Must be secure, tested, and documented
• Adhere to the Drips Wave design and engineering standards
• Ensure full test coverage for new logic
• Specifically focused on backend system optimization and security integrity

Suggested execution

Fork the repo and create a branch
git checkout -b feature/be-conduct-security-audit-on-transaction-signer
Implement changes

Review existing implementation in Transaction Signer
Apply changes: Conduct security audit on Transaction Signer
Ensure robust error handling and logging
Test and commit

Run unit and integration tests for Transaction Signer
Cover edge cases and validate security assumptions
Include test output and security notes in the PR
Example commit message
feat(backend): conduct security audit on Transaction Signer

Guidelines

Complexity: High (200 points)
Assignment required before starting
PR description must include: Closes #[issue_id]

[Temi-suwa18]

@Temi-suwa18 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I would like to work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Temi-suwa18 to this issue.

[drips-wave]

Congratulations, @Temi-suwa18! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @Temi-suwa18: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[drips-wave]

This issue has been completed by @Temi-suwa18 as part of the Stellar Wave Program's 5th Wave 🥳

😎 @Temi-suwa18: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

🧑‍💻 Repo maintainers: How'd the contributor do? Leave a review to share your experience working with them.