Cached · just now
91/100 SECURITY SCORE

Certificate Information

Subject
CN=blockstream.info
Issuer
C=US, O=Let's Encrypt, CN=R13
Valid From
January 09, 2026
Valid Until
April 09, 2026 86 days
Public Key
RSA 2048 bit Adequate
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
45:DE:00:63:E3:D1:27:97:47:4B:AE:83:3C:EA:04:87:76:C5:12:81:DA:94:8B:8F:8D:61:BC:A6:DD:40:99:95
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
Basic
default-src; script-src; img-src; +3 more
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
no-referrer
Permissions-Policy
Missing
Not configured
Recommendations
  • Consider adding 'preload' to HSTS for maximum security
  • Improve CSP by adding more specific directives and removing 'unsafe-inline'
  • 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

Subject Alternative Names

2 domains