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96/100 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
Configured (Restricts certificate issuance)
Current Issuer
Authorized (Matches CAA policy)
Authorized CAs
Recommendations
  • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts
  • Consider adding 'issuewild' records to control wildcard certificate issuance