Cached · just now
93/100 SECURITY SCORE

Certificate Information

Subject
CN=proton.me
Issuer
C=US, O=Let's Encrypt, CN=R13
Valid From
March 21, 2026
Valid Until
June 19, 2026 76 days
Public Key
RSA 4096 bit Strong
Signature Algorithm
SHA256-RSA
SHA-256 Fingerprint
D4:3D:26:E6:70:2B:9C:14:84:55:8A:6E:D4:EB:1E:9B:5B:D4:40:9E:8D:2D:6A:79:E3:FE:56:CE:5C:D0:F5:95
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
Excellent
max-age=31536000; includeSubDomains; preload
Content-Security-Policy
Basic
default-src; media-src; connect-src; +9 more Analyze
Content-Security-Policy-Report-Only
Missing
Not configured Analyze
X-Frame-Options
Missing
Not configured
X-Content-Type-Options
Good
nosniff
Referrer-Policy
Good
strict-origin-when-cross-origin
Permissions-Policy
Missing
Not configured
Recommendations
  • Improve CSP by adding more specific directives and removing 'unsafe-inline'
  • Add X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking
  • 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)
Recommendations
  • Consider using critical flag (flags=128) for stricter CAA enforcement
  • Consider adding 'iodef' records to receive notifications about unauthorized certificate issuance attempts
  • Consider adding 'issuewild' records to control wildcard certificate issuance

Subject Alternative Names

5 domains