Open
Cached
·
just now
93/100
SECURITY SCORE
Certificate Information
Subject
CN=nic.cz
Issuer
C=US, O=Let's Encrypt, CN=E7
Valid From
October 25, 2025
Valid Until
January 23, 2026
79 days
Public Key
ECDSA
384 bit
(P-384)
Strong
Signature Algorithm
ECDSA-SHA384
SHA-256 Fingerprint
69:DB:F4:B6:F7:38:6A:A3:30:3D:E1:24:39:6A:12:4D:97:33:DB:E5:B7:3E:DF:D5:6A:74:8A:71:AA:B6:78:81
Alternative Names
Security Configuration
TLS Protocols
TLS 1.2
TLS 1.3
Forward Secrecy
Supported
(Modern clients use PFS)
HTTP Security Headers
Status
Strict-Transport-Security
Good
max-age=31536000; includeSubDomains
Content-Security-Policy
Good
default-src; script-src; object-src; +7 more
X-Frame-Options
Excellent
DENY
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Present
same-origin
Permissions-Policy
Missing
Not configured
Recommendations
- • Consider adding 'preload' to HSTS for maximum security
- • Strengthen CSP by removing 'unsafe-eval'
- • Consider adding Permissions-Policy to control browser features
CAA Records (Certificate Authority Authorization)
CAA Records
Not Configured
(Any CA can issue certificates)
CAA Issues
- • No CAA records configured - any CA can issue certificates
Recommendations
- • Implement CAA records to restrict which CAs can issue certificates for your domain
- • This adds an extra layer of security against unauthorized certificate issuance
- • Example: Add CAA record 'example.com. CAA 0 issue "letsencrypt.org"'
- • Consider adding 'iodef' record to receive security incident reports