# Uncategorized **URL:** https://community.blockcerts.org/c/uncategorized/1.md [Latest](https://community.blockcerts.org/latest.md) · [Categories](https://community.blockcerts.org/categories.md) --- ## [Welcome to the Blockcerts community](https://community.blockcerts.org/t/welcome-to-the-blockcerts-community/8)
**Author:** [@system](https://community.blockcerts.org/u/system)\ **Replies:** 0\ **Last updated:** [March 8, 2017, 11:37pm UTC](https://community.blockcerts.org/t/welcome-to-the-blockcerts-community/8 "2017-03-08T23:37:13Z")
Blockcerts is an open standard for creating, issuing, viewing, and verifying blockchain-based digital records. These records are registered on the blockchain, cryptographically signed, tamper-proof, and shareable. The go… --- ## [Custom Certificate](https://community.blockcerts.org/t/custom-certificate/2983)
**Author:** [@sreenumalae](https://community.blockcerts.org/u/sreenumalae)\ **Replies:** 11\ **Last updated:** [April 4, 2026, 2:45am UTC](https://community.blockcerts.org/t/custom-certificate/2983 "2026-04-04T02:45:23Z")
Instead of creating a certificate using different logos. I have an LMS where I create a certificate. Is it possible to pass that certificate to BlockCerts and authenticate that certificate using blockchain? --- ## [Demande d'aide à la communauté](https://community.blockcerts.org/t/demande-daide-a-la-communaute/3924)
**Author:** [@RAIS71](https://community.blockcerts.org/u/RAIS71)\ **Replies:** 1\ **Last updated:** [October 22, 2025, 11:19am UTC](https://community.blockcerts.org/t/demande-daide-a-la-communaute/3924 "2025-10-22T11:19:44Z")
Peut-on utiliser la blockcert pour émettre et vérifier de Certificat dans un projet php ? --- ## [Looking for Best Practices for Verifying Blockcerts Without Central Authority?](https://community.blockcerts.org/t/looking-for-best-practices-for-verifying-blockcerts-without-central-authority/3857)
**Author:** [@marcellosals](https://community.blockcerts.org/u/marcellosals)\ **Replies:** 1\ **Last updated:** [July 17, 2025, 1:21pm UTC](https://community.blockcerts.org/t/looking-for-best-practices-for-verifying-blockcerts-without-central-authority/3857 "2025-07-17T13:21:45Z")
Hi everyone, I am fairly new to the Blockcerts ecosystem and fascinated by how it enables truly decentralized credential verification. I have been experimenting with issuing and verifying certificates.., but I am curiou… --- ## [No se ha podido obtener el perfil del emisor](https://community.blockcerts.org/t/no-se-ha-podido-obtener-el-perfil-del-emisor/3796)
**Author:** [@Gerataker3000](https://community.blockcerts.org/u/Gerataker3000)\ **Replies:** 2\ **Last updated:** [April 28, 2025, 3:13pm UTC](https://community.blockcerts.org/t/no-se-ha-podido-obtener-el-perfil-del-emisor/3796 "2025-04-28T15:13:36Z")
Hola comunidad, estoy configurando la emisión de certificados digitales con Blockcerts y ya generé mi plantilla en Cert Tools. Al momento de registrar el emisor, ya tengo una URL válida que apunta a mi archivo issuer.jso… --- ## [cert\_issuer.errors.InsufficientFundsError: Please add 500000000000000 wei](https://community.blockcerts.org/t/cert-issuer-errors-insufficientfundserror-please-add-500000000000000-wei/2893)
**Author:** [@sreenumalae](https://community.blockcerts.org/u/sreenumalae)\ **Replies:** 5\ **Last updated:** [April 9, 2025, 6:53am UTC](https://community.blockcerts.org/t/cert-issuer-errors-insufficientfundserror-please-add-500000000000000-wei/2893 "2025-04-09T06:53:04Z")
For the below command I’m facing the issue python3 /cert-issuer/cert\_issuer -c /cert-issuer/conf.ini WARNING - Your app is configured to skip the wifi check when the USB is plugged in. Read the documentation to ensure … --- ## [Issue with Certificate Upload - "Invalid Credential" Error](https://community.blockcerts.org/t/issue-with-certificate-upload-invalid-credential-error/3703)
**Author:** [@sreenumalae](https://community.blockcerts.org/u/sreenumalae)\ **Replies:** 14\ **Last updated:** [April 9, 2025, 6:45am UTC](https://community.blockcerts.org/t/issue-with-certificate-upload-invalid-credential-error/3703 "2025-04-09T06:45:52Z")
I have used Cert-tools to create unsigned certificates and Cert-issuer (with Ethereum) to generate signed certificates. However, when I upload the signed certificate to the app, I encounter the following error: “Invali… --- ## [Does Blockcerts supports Off-Chain storage solution?](https://community.blockcerts.org/t/does-blockcerts-supports-off-chain-storage-solution/3629)
**Author:** [@pmohite13](https://community.blockcerts.org/u/pmohite13)\ **Replies:** 0\ **Last updated:** [August 9, 2024, 7:41pm UTC](https://community.blockcerts.org/t/does-blockcerts-supports-off-chain-storage-solution/3629 "2024-08-09T19:41:48Z")
I am new to blockchain technology so please excuse my basic question. Does Blockcerts supports any other little less expensive chains then bitcoin or Ethereum in terms of transaction and other fees? Or may be hybrid solu… --- ## [Service Endpoint for BlockCerts in W3C DID Document](https://community.blockcerts.org/t/service-endpoint-for-blockcerts-in-w3c-did-document/3597)
**Author:** [@garyrob](https://community.blockcerts.org/u/garyrob)\ **Replies:** 1\ **Last updated:** [June 3, 2024, 10:01am UTC](https://community.blockcerts.org/t/service-endpoint-for-blockcerts-in-w3c-did-document/3597 "2024-06-03T10:01:43Z")
If I have a W3C DID Document and I want to have a serviceEndpoint that points to a BlockCerts credential such as MIT’s digital diploma, chatGPT suggests something along the lines of the following. I’m wondering if that’s… --- ## [Cert-tools V3 credential](https://community.blockcerts.org/t/cert-tools-v3-credential/3295)
**Author:** [@mary.tellez](https://community.blockcerts.org/u/mary.tellez)\ **Replies:** 6\ **Last updated:** [January 23, 2024, 4:11pm UTC](https://community.blockcerts.org/t/cert-tools-v3-credential/3295 "2024-01-23T16:11:41Z")
Hello!: When i try instantiate-certificate-batch -c conf.ini with the default config returns cert\_schema.errors.BlockcertValidationError: ‘nonce’ is a required property Please help. --- ## [Is Blockchain Technology Safe for Issuing Digital Certificates and Badges](https://community.blockcerts.org/t/is-blockchain-technology-safe-for-issuing-digital-certificates-and-badges/3497)
**Author:** [@Suryanm1090](https://community.blockcerts.org/u/Suryanm1090)\ **Replies:** 1\ **Last updated:** [January 17, 2024, 2:12pm UTC](https://community.blockcerts.org/t/is-blockchain-technology-safe-for-issuing-digital-certificates-and-badges/3497 "2024-01-17T14:12:24Z")
The safety and security of blockchain technology for issuing digital certificates and badges are key concerns in today’s increasingly digital and credential-driven world. Blockchain, known for its decentralized, transpar… --- ## [Cert-tools error: AttributeError: 'str' object has no attribute 'isoformat'. Did you mean: 'format'?](https://community.blockcerts.org/t/cert-tools-error-attributeerror-str-object-has-no-attribute-isoformat-did-you-mean-format/3222)
**Author:** [@jhdezctza](https://community.blockcerts.org/u/jhdezctza)\ **Replies:** 7\ **Last updated:** [October 29, 2023, 3:36pm UTC](https://community.blockcerts.org/t/cert-tools-error-attributeerror-str-object-has-no-attribute-isoformat-did-you-mean-format/3222 "2023-10-29T15:36:53Z")
help me please: cert-tools error AttributeError: ‘str’ object has no attribute ‘isoformat’. Did you mean: ‘format’? --- ## [Professional licenses](https://community.blockcerts.org/t/professional-licenses/3467)
**Author:** [@Osler](https://community.blockcerts.org/u/Osler)\ **Replies:** 2\ **Last updated:** [September 1, 2023, 2:57pm UTC](https://community.blockcerts.org/t/professional-licenses/3467 "2023-09-01T14:57:23Z")
Question about credentials related to licenses, what happens if a license is expired, inactive, or terminated? Will the person be able to show they still have the credential even though they technically do not anymore? --- ## [Blockcert Issue Cost](https://community.blockcerts.org/t/blockcert-issue-cost/3428)
**Author:** [@kyaaqba](https://community.blockcerts.org/u/kyaaqba)\ **Replies:** 0\ **Last updated:** [June 22, 2023, 1:38pm UTC](https://community.blockcerts.org/t/blockcert-issue-cost/3428 "2023-06-22T13:38:42Z")
I want to ask how much it costs these days to issue a certificate, using Bitcoin and Ethereum? and is batching more certificates an excellent idea to lower cost? Thanks, Karam Yaaqba --- ## [Verifier implementation](https://community.blockcerts.org/t/verifier-implementation/3344)
**Author:** [@takeura](https://community.blockcerts.org/u/takeura)\ **Replies:** 1\ **Last updated:** [January 3, 2023, 1:06pm UTC](https://community.blockcerts.org/t/verifier-implementation/3344 "2023-01-03T13:06:46Z")
Is there any difference between the Blockcerts Universal Verifier at blockcerts.org and the implementation of cert-verifier(python) in the repository? --- ## [How do I add the name to my certificate?](https://community.blockcerts.org/t/how-do-i-add-the-name-to-my-certificate/3273)
**Author:** [@jhdezctza](https://community.blockcerts.org/u/jhdezctza)\ **Replies:** 1\ **Last updated:** [August 25, 2022, 10:28am UTC](https://community.blockcerts.org/t/how-do-i-add-the-name-to-my-certificate/3273 "2022-08-25T10:28:01Z")
How did you add the name when instantiating my certificate with version V3? thanks --- ## [Is blockcerts.org related with Blockcerts.jp?](https://community.blockcerts.org/t/is-blockcerts-org-related-with-blockcerts-jp/3217)
**Author:** [@sleepingdroid](https://community.blockcerts.org/u/sleepingdroid)\ **Replies:** 1\ **Last updated:** [June 27, 2022, 7:21pm UTC](https://community.blockcerts.org/t/is-blockcerts-org-related-with-blockcerts-jp/3217 "2022-06-27T19:21:10Z")
I have link from Blockcerts.jp how can i use with blockcerts.org is it same website? --- ## [Blockcerts aplicados al sistema educativo](https://community.blockcerts.org/t/blockcerts-aplicados-al-sistema-educativo/3186)
**Author:** [@legui\_1915](https://community.blockcerts.org/u/legui_1915)\ **Replies:** 0\ **Last updated:** [May 19, 2022, 6:26pm UTC](https://community.blockcerts.org/t/blockcerts-aplicados-al-sistema-educativo/3186 "2022-05-19T18:26:19Z")
Buenas soy Roberto. Estoy investigando acerca de esta tecnología aplicada al sistema administrativo de la la educacion en todos sus niveles. me podrían dar puntos claves donde para continuar mi linea de investigación, … --- ## [Blockcert-v3 Invalid JSON-LD syntax; @context must be an object](https://community.blockcerts.org/t/blockcert-v3-invalid-json-ld-syntax-context-must-be-an-object/3126)
**Author:** [@mposdev21](https://community.blockcerts.org/u/mposdev21)\ **Replies:** 2\ **Last updated:** [April 6, 2022, 4:19pm UTC](https://community.blockcerts.org/t/blockcert-v3-invalid-json-ld-syntax-context-must-be-an-object/3126 "2022-04-06T16:19:03Z")
Hi, I am trying to run the python application cert\_issuer and when I use the sample verifiable\_credential.json, I end up with an issue: pyld.jsonld.JsonLdError: (‘Invalid JSON-LD syntax; @context must be an object.’,) … --- ## [Cert-tools create-certificate-template not found](https://community.blockcerts.org/t/cert-tools-create-certificate-template-not-found/2559)
**Author:** [@tommparekh](https://community.blockcerts.org/u/tommparekh)\ **Replies:** 1\ **Last updated:** [March 16, 2022, 9:04pm UTC](https://community.blockcerts.org/t/cert-tools-create-certificate-template-not-found/2559 "2022-03-16T21:04:09Z")
I ran pip install command but do not see create-certificate-template.py. How do I proceed? Here is a link I used: Steps I followed: Thanks --- ## [Could blockcerts be used as a digital signature for any hashable docs?](https://community.blockcerts.org/t/could-blockcerts-be-used-as-a-digital-signature-for-any-hashable-docs/3003)
**Author:** [@7.sss](https://community.blockcerts.org/u/7.sss)\ **Replies:** 1\ **Last updated:** [November 15, 2021, 7:51am UTC](https://community.blockcerts.org/t/could-blockcerts-be-used-as-a-digital-signature-for-any-hashable-docs/3003 "2021-11-15T07:51:06Z")
Dear Community, What an amazing inititative for educational validation and transparency. I’ve always held a desire to have the ability to piece credentials for later distribution and sharing. Thank you for doing this … --- ## [Installing explorer lookup in blockcert-viewer](https://community.blockcerts.org/t/installing-explorer-lookup-in-blockcert-viewer/2999)
**Author:** [@mikhatanu](https://community.blockcerts.org/u/mikhatanu)\ **Replies:** 2\ **Last updated:** [November 15, 2021, 7:39am UTC](https://community.blockcerts.org/t/installing-explorer-lookup-in-blockcert-viewer/2999 "2021-11-15T07:39:11Z")
Hello all, i want to ask about how to install explorer-lookup into blockcert verifier as i need to change the some files in the explorer-lookup/src. I tried installing blockcert-verifier first using “npm i @blockcerts/b… --- ## [Blockcert-verifier headers when verifying](https://community.blockcerts.org/t/blockcert-verifier-headers-when-verifying/2996)
**Author:** [@mikhatanu](https://community.blockcerts.org/u/mikhatanu)\ **Replies:** 4\ **Last updated:** [November 9, 2021, 7:07pm UTC](https://community.blockcerts.org/t/blockcert-verifier-headers-when-verifying/2996 "2021-11-09T19:07:52Z")
Anyone know where can i add headers request to blockcert-verifier serviceurl? The web i use for verifying certificates are private and it uses bearer token in headers, not token in the url --- ## [What is the workflow of the projectt?](https://community.blockcerts.org/t/what-is-the-workflow-of-the-projectt/2981)
**Author:** [@vmarella](https://community.blockcerts.org/u/vmarella)\ **Replies:** 1\ **Last updated:** [November 2, 2021, 4:07pm UTC](https://community.blockcerts.org/t/what-is-the-workflow-of-the-projectt/2981 "2021-11-02T16:07:59Z")
Can someone briefly explain how the project works? What kind of hash function are used in developing the fingerprint of the documents? --- ## [Research subject](https://community.blockcerts.org/t/research-subject/2991)
**Author:** [@GATTA-BI](https://community.blockcerts.org/u/GATTA-BI)\ **Replies:** 0\ **Last updated:** [October 31, 2021, 8:57am UTC](https://community.blockcerts.org/t/research-subject/2991 "2021-10-31T08:57:29Z")
Hello ; Help me please. I am a Blockchain Research Master 2 student and I need to find a research topic to support my Master. But, the subjects that I find, they let me know are engineering subjects. So suggest some Blo… --- ## [Mémoire de recherche (Master 2 Blockchain)](https://community.blockcerts.org/t/memoire-de-recherche-master-2-blockchain/2990)
**Author:** [@GATTA-BI](https://community.blockcerts.org/u/GATTA-BI)\ **Replies:** 0\ **Last updated:** [October 31, 2021, 8:22am UTC](https://community.blockcerts.org/t/memoire-de-recherche-master-2-blockchain/2990 "2021-10-31T08:22:07Z")
Bonjour ; Aidez moi s’il vous plaît. Je suis étudiant en Master 2 de recherche Blockchain et je dois trouver un sujet de recherche pour soutenir mon Master. Mais, les sujets que je trouve, on me faire savoir que ce sont… --- ## [Problem with the implementation of verifying document with verifier-life.js](https://community.blockcerts.org/t/problem-with-the-implementation-of-verifying-document-with-verifier-life-js/2973)
**Author:** [@dampap](https://community.blockcerts.org/u/dampap)\ **Replies:** 11\ **Last updated:** [October 13, 2021, 4:46pm UTC](https://community.blockcerts.org/t/problem-with-the-implementation-of-verifying-document-with-verifier-life-js/2973 "2021-10-13T16:46:33Z")
I cant implement verifier-life.js in my front end for simple verification of json files, I get the response “cant get Transaction Id”. I will attach my code from front-end as well as the response from console log. \*\* … --- ## [Exposing public identity in school official website - strict requirement?](https://community.blockcerts.org/t/exposing-public-identity-in-school-official-website-strict-requirement/2977)
**Author:** [@mickeyf](https://community.blockcerts.org/u/mickeyf)\ **Replies:** 1\ **Last updated:** [October 11, 2021, 4:39pm UTC](https://community.blockcerts.org/t/exposing-public-identity-in-school-official-website-strict-requirement/2977 "2021-10-11T16:39:52Z")
Hi, New to Blockcerts! I was whether issuers need an official website to use Blockcerts. I think Blockcerts could have a real use for my own project, but unfortunately, my issuers will not have official websites. Would… --- ## [Linking certification to traceability](https://community.blockcerts.org/t/linking-certification-to-traceability/2959)
**Author:** [@WineLedger](https://community.blockcerts.org/u/WineLedger)\ **Replies:** 1\ **Last updated:** [September 29, 2021, 11:39am UTC](https://community.blockcerts.org/t/linking-certification-to-traceability/2959 "2021-09-29T11:39:56Z")
Can you please advise as to how BlockCerts can assist with linking certified documents to product traceability in the supply chain. --- ## [Neat project - token?](https://community.blockcerts.org/t/neat-project-token/2961)
**Author:** [@pascal](https://community.blockcerts.org/u/pascal)\ **Replies:** 1\ **Last updated:** [September 28, 2021, 1:58pm UTC](https://community.blockcerts.org/t/neat-project-token/2961 "2021-09-28T13:58:27Z")
Neat project. Are you guys planning on issuing a token, and what would the value proposition be for someone interested in acquiring it? [Next page](https://community.blockcerts.org/c/uncategorized/1.md?page=1)