Weak Key Detector

Detect weak cryptographic keys in SSL certificates

About Weak Key Detector

Cryptographic key strength is critical to SSL/TLS security. Our Weak Key Detector analyzes the keys in your server's certificate chain, checking for known weak key sizes, deprecated algorithms, and insecure configurations. It supports RSA, ECDSA, and Ed25519 keys and flags any key that falls below modern security standards.

How to Use

1Enter the domain name you want to test in the input field.
2Click "Check" to analyze the server's cryptographic keys.
3Review each check result and follow recommendations for flagged issues.

Use Cases

•Audit key strength across all certificates in your infrastructure
•Identify certificates using deprecated RSA-1024 or SHA-1 signatures
•Ensure compliance with industry standards like PCI DSS and NIST
•Verify key strength before deploying new certificates to production
•Compare key strength across multiple domains and environments

Frequently Asked Questions

RSA keys below 2048 bits and ECDSA keys below 256 bits are considered weak by modern standards. The tool flags these as warnings and recommends upgrading.

Yes, weak keys can be factored or broken with modern computing power. RSA-512 can be cracked in hours, and RSA-1024 is considered borderline with nation-state resources.

Yes, ECDSA and Ed25519 keys provide equivalent security to RSA with much smaller key sizes. ECDSA-256 is comparable to RSA-3072, and Ed25519 offers excellent security with fast performance.

Tips & Best Practices

•Use RSA keys of at least 2048 bits, preferably 4096 bits
•Consider ECDSA keys (P-256 or P-384) for better performance and security
•Replace weak keys immediately — they provide no real security
•Monitor key strength across your entire certificate infrastructure

Technical Details

Algorithms: RSA, ECDSA, Ed25519 key strength analysis
Minimum: RSA 2048-bit, ECDSA P-256, Ed25519
Recommended: RSA 4096-bit, ECDSA P-384
Output: Key strength assessment with upgrade recommendations