blockchain.grantthornton.global

Issued by Let's Encrypt Authority X3

About this certificate

This digital certificate with serial number 04:e0:5c:1d:28:47:03:80:8e:1c:74:97:a9:de:df:8f:d6:46 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=blockchain.grantthornton.global

Let's Encrypt

Organization: Let's Encrypt
Country: US

This certificate has expire since

Certificate Details

Serial Number (hex): 04:e0:5c:1d:28:47:03:80:8e:1c:74:97:a9:de:df:8f:d6:46
Serial Number (int): 424794834286474979725814798115516344948294
Serial Number lenght: 139 bits, 18 octets

SubjectKeyId: 2e:c2:9b:09:c7:30:fc:2f:30:c9:0c:8e:f5:f5:15:6f:8d:e2:f1:8c
AuthorityKeyId: a8:4a:6a:63:04:7d:dd:ba:e6:d1:39:b7:a6:45:65:ef:f3:a8:ec:a1

Fingerprint (sha1): 16:77:aa:c6:ed:0e:58:0d:51:76:70:6b:ca:47:8d:6c:f0:89:87:b4
Fingerprint (sha256): 0a:43:8a:55:ea:43:9c:f1:a6:d7:09:b2:83:f8:d2:98:60:7a:f2:05:fb:c1:6c:53:90:1a:2f:38:43:6e:17:06

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 blockchain.grantthornton.global

1

DNS Names

0

Email Addresses

0

IP Addresses

Advanced Certificate Properties

Tehnical certificate details for blockchain.grantthornton.global

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

blockchain.grantthornton.global

Other certificates including the domain name grantthornton.global

(limited to 100 certificates)

Certificate

The complete raw certificate details for blockchain.grantthornton.global 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 424794834286474979725814798115516344948294
 . . . . . . . . [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 2019-06-24 05:05:53 +0000 UTC
 . . . . . . . . . . . . [c:0|t:23|false] UTCTime 2019-09-22 05:05:53 +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 'blockchain.grantthornton.global'
 . . . . . . . . [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 916642394109981958902267515501012078651749675609281124895549374687712770333419905662998320857586016187196584259313342827209465275452273185752757373282001360091842848865291398216337013131597462467962117712112662480607606097692607451025209289162497433130788111469125191594484740567505257280092573676156610445878648699482950243968646066490582558805840862588621420366807319639491414596653772677902968684129216050273274113983564088705231513082201683378658953338709262477279333950799976286522478921956828956493252798445489742174876283600855443962992160925309901367984997103419530989296345493927838562377104343106693839533388217034614327371927061644442281122853467843298319185348320999975433231600792045689382718368900872166696010038409514079123544108015996817608417097750431583295885617289033043594183283900565501655939174848116748111672266414916435152938126245465981737355990213992880507722666868702071136642567343532374044051939242509025844229058712236846737954900848368448503112987189759657127217887138829882029689271678906282970009037694972150129738516585548105596099643668237176960784821759959692442726280308984751758636129141931259510453709493204823022110475003820499754598312934868403635906314925991949143359396432731986002249724173
 . . . . . . . . . . . . . . . . . . . . [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)
							2ec29b09c730fc2f30c90c8ef5f5156f8de2f18c
 . . . . . . . . . . . . . . . . [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 (35 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:16|true] SEQUENCE, SEQUENCE OF 
 . . . . . . . . . . . . . . . . . . . . . . . . . . . . [c:2|t:2|false] IA5String 'blockchain.grantthornton.global'
 . . . . . . . . . . . . . . . . [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 (244 bytes)
 . . . . . . . . . . . . . . . . . . . . . . . . [c:0|t:4|false] OCTET STRING (241 bytes)
							00ef0076006f5376ac31f03119d89900a45115ff77151c11d902c10029068db2089a37d9130000016b881741f900000403004730450221009eadb17ee6127ecda02d41217518e4a5639e3f7ca0364e4a0844a1f45a99ab41022069cc0a5359a07a7c1fb21d6d9aece878453829a97cb3087718bb6235904cf96d00750063f2dbcde83bcc2ccf0b728427576b33a48d61778fbd75a638b1c768544bd88d0000016b88174136000004030046304402206624dee858402c9fcf6d7aa9a1cd3348cc1443c1e03242b2f0ec72fe75f6ebec02203a16682e7c0c9fb326d19ade5d841bbb197e3080600c3e95c33f5473648125a6
 . . . . [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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