www.polygraphia.com

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 03:47:51:e6:26:39:ea:34:3a:60:35:90:0e:a5:68:06:94:56 was issued on by Let's Encrypt.

This certificate has already expired and will cause a warning or error message in the browser it's still listed on this site to allow you to look back on previously issued certificates. If we have found any compliance issues with this certificate they will be shown below. I hope this certificate review is providing you the detailed information in a simple form you where looking for.


We have idenified some issues with this certificate:
  • Subscriber Certificate: commonName is deprecated. (BRs: 7.1.4.2.2)

Certificate Subject

CN=www.polygraphia.com

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 03:47:51:e6:26:39:ea:34:3a:60:35:90:0e:a5:68:06:94:56
Serial Number (int): 285605768317923464876020427119417968989270
Serial Number lenght: 138 bits, 18 octets

SubjectKeyId: f2:a0:3f:1b:a9:ba:e1:e2:86:0e:ae:b1:6d:99:79:9f:8f:c8:23:ce
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): b5:2a:43:83:29:3d:50:79:bb:aa:fa:5f:b3:b4:e1:2b:15:1c:83:e8
Fingerprint (sha256): c3:5f:6f:08:96:4c:d9:34:b7:f5:f5:dc:63:4a:13:96:21:66:ba:89:d6:16:f8:55:b2:9b:06:22:af:a1:28:93

Issuing Certificate URL: http://cert.int-x3.letsencrypt.org/

Revocation information

OCSP Server: http://ocsp.int-x3.letsencrypt.org

Check the revocation status for certificate www.polygraphia.com

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for www.polygraphia.com

Public Key Algorithm

RSA

Key Size

4096

Signature Algorithm

SHA256 with RSA

Key Usage

Digital Signature
Key Encipherment

Extended Key Usages

Server Authentication
Client Authentication

Extensions

9 extensions
No unhandled critical extensions

CA Certificate

This is not a CA certificate

Subject Alternative Names

www.polygraphia.com

Other certificates including the domain name polygraphia.com

(limited to 100 certificates)

Certificate

The complete raw certificate details for www.polygraphia.com in PEM and ASN.1 format.

Certificate (PEM)

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----

Public Key (PEM)

-----BEGIN PUBLIC KEY-----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-----END PUBLIC KEY-----

ASN.1 decoded

 [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:2|t:0|true] OtherName 
 . . . . . . . . . . . . [c:0|t:2|false] INTEGER 2
 . . . . . . . . [c:0|t:2|false] INTEGER 285605768317923464876020427119417968989270
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption)
 . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.6 (countryName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'US'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.10 (organizationName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Let's Encrypt'
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'Let's Encrypt Authority X3'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-12-11 17:56:55 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2020-03-10 17:56:55 +0000 UTC
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:17|true] SET, SET OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.4.3 (commonName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:19|false] PrintableString 'www.polygraphia.com'
 . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.1 (rsaEncryption)
 . . . . . . . . . . . . . . . . [c:0|t:5|false] NULL 
 . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (4208 bits)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 831572227022105546793504195212315277694212358568594512889620108430688294855232208711656310030476268227111693971357544281408988627177479584803969321563559592476072647103119012958773618297142595522609611296856766464792823063248600506024144143637243788166294401021659385235612298354707276581344559512404829609027850086020710242433140029193068682535766372946583575500385534036234626440201944743042302144088574646455180456279401144515350914665102616136297778314671549034397510020793772482668102638578699166599475335352046426494727577638427933389977626152618566147121728956262242386904481389247469661951267438022856676972168810127931902028171260759084008571793393206173071755759530649194785501892763092024919337094745178834189946259573431933215630434203221399640124401007155264567445857063149143560535476201104224942296450273151713576595505304126677005298702154608092154583199774730429331019266227375329222171847344414246270717769148616691293213260271242094110530125221202221725441145003417989067607355963624095401742132868731054933691396385099914618556349756606384759600416724048713528772260418524356051538943666491840363363734058196570248871360421310209812901224558190515717538045531145235096060246555621864542134713137317006596311947543
 . . . . . . . . . . . . . . . . . . . . [c:0|t:2|false] INTEGER 65537

 . . . . . . . . [c:2|t:3|true] ORAddress 
 . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.15 (keyUsage)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (4 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:3|false] BIT STRING (3 bits)
							05a0
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.37 (extKeyUsage)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.1 (serverAuth)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.3.2 (clientAuth)
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.19 (basicConstraints)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:1|false] BOOLEAN true
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (2 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.14 (subjectKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (22 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (20 bytes)
							f2a03f1ba9bae1e2860eaeb16d99799f8fc823ce
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.35 (authorityKeyIdentifier)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (24 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:0|false] OtherName a84a6a63047dddbae6d139b7a64565eff3a8eca1
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.1.1 (authorityInfoAccess)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (99 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.1 (ocsp)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://ocsp.int-x3.letsencrypt.org'
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.48.2 (caIssuers)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:6|false] IA5String 'http://cert.int-x3.letsencrypt.org/'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.17 (subjectAltName)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (23 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'www.polygraphia.com'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.5.29.32 (certificatePolicies)
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (69 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 2.23.140.1.2.1 (Domain Validation Certificates Policy)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.44947.1.1.1
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.5.5.7.2.1 (cps)
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:22|false] IA5String 'http://cps.letsencrypt.org'
 . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.3.6.1.4.1.11129.2.4.2
 . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (247 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (244 bytes)
							00f2007700f095a459f200d18240102d2f93888ead4bfe1d47e399e1d034a6b0a8aa8eb2730000016ef6523f5d0000040300483046022100f1376a5def2bcb5532c2ef9579a3352ea65b2485ba20fddd59f3983756c97f1c022100e41cd7ed70067b660a2302ae2f594a8947b1aadb1f9e5633f109c69888059471007700b21e05cc8ba2cd8a204e8766f92bb98a2520676bdafa70e7b249532def8b905e0000016ef65241450000040300483046022100f35e11efda805d890695deb3ab5ad3b7fb45a4bddb62bff666f0ea6a82cd40d9022100b564d3b7cc9cb630bf2b8f76cd494c2f27dfa0e7b6538ae64af1a3465fbff6dd
 . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . [c:0|t:6|false] OBJECT IDENTIFIER 1.2.840.113549.1.1.11 (sha256WithRSAEncryption)
 . . . . . . . . [c:0|t:5|false] NULL 
 . . . . [c:0|t:3|false] BIT STRING (2048 bits)
		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