TLS Certificates for Blockchain Domains Current Options and Gaps

As decentralized naming systems such as Ethereum Name Service (ENS), Unstoppable Domains, and Handshake gain traction as alternatives to traditional DNS-based domains, a major unresolved issue remains the integration of Transport Layer Security (TLS) certificates. TLS is a foundational technology in web security, enabling encrypted connections and authenticating websites through the familiar padlock icon in browsers. Without proper TLS support, blockchain-based domains struggle to gain user trust, especially for applications that handle sensitive data or financial transactions. Yet, because blockchain domains do not operate within the conventional DNS root system overseen by ICANN, issuing and validating TLS certificates for them presents unique technical and procedural challenges. The current landscape offers some partial solutions, but significant gaps remain in achieving native, seamless, and secure HTTPS functionality for Web3 domains.

Traditional TLS certificates are issued by Certificate Authorities (CAs), centralized entities trusted by browser vendors to vouch for the legitimacy of domain ownership. The issuance process typically requires domain control verification through DNS record updates or HTTP file hosting on the domain’s web server. However, blockchain domains such as those ending in .eth or .crypto are not recognized by ICANN and cannot be resolved through standard DNS infrastructure. As a result, CAs cannot complete their standard validation process, and browsers do not natively support these domains. This lack of integration effectively blocks blockchain domains from obtaining certificates through widely trusted CAs like Let’s Encrypt, DigiCert, or GlobalSign.

To work around this limitation, some projects have adopted the use of gateway services that map blockchain domains to traditional DNS domains that can obtain TLS certificates. For instance, the eth.limo and eth.link services resolve ENS names like alice.eth to an HTTPS-enabled subdomain such as alice.eth.limo. These gateway operators act as intermediaries, terminating HTTPS connections using valid TLS certificates for the Web2-compatible domain. While this approach allows users to access blockchain-hosted content over a secure HTTPS connection, it reintroduces a layer of centralization. The gateway operator holds the TLS keys and could theoretically alter, block, or log traffic. Although the content itself might be stored on decentralized networks like IPFS and verified through content hashes, the delivery path remains dependent on trusted intermediaries.

Unstoppable Domains offers another partial solution by integrating with Cloudflare to provide HTTPS access to domains such as alice.crypto through the use of DNS-over-HTTPS (DoH) and Cloudflare’s gateway. Cloudflare handles the TLS termination, routing traffic securely while resolving blockchain domains via a custom resolution layer. However, this model also depends on a centralized party and does not reflect the permissionless ethos of Web3. Furthermore, this solution is limited to certain browsers and configurations, and users may be unaware that their connection is mediated by a centralized service provider.

A more decentralized and ambitious solution involves self-signed TLS certificates or experimental CA models that issue certificates for blockchain domains directly. The challenge here is that modern browsers are tightly locked to the existing CA trust store, and self-signed certificates or certificates from unrecognized CAs trigger security warnings, causing user confusion or rejection of the connection altogether. Projects such as CertCoin and Namecoin have explored decentralized public key infrastructures (DPKIs) where domain owners publish public keys directly on-chain, which can then be used to verify TLS sessions. However, these models require browser-level changes or plugins to recognize and trust the new PKI sources, limiting their mainstream usability.

Another emerging concept involves using Web3-native methods of proving domain control for certificate issuance. For example, a blockchain domain owner could sign a message with their wallet’s private key and present it to a Web3-aware CA to obtain a certificate. This would require building new certificate authority infrastructure that understands smart contract ownership and verification methods across chains like Ethereum, Polygon, or Solana. While technically feasible, this model would still face the browser compatibility problem—unless browser vendors agree to include these new CAs in their trust root stores, users will continue to encounter untrusted certificate warnings.

There is also ongoing research into adapting existing standards, such as the ACME protocol used by Let’s Encrypt, to support decentralized verification hooks. Theoretically, if a CA could query a smart contract or blockchain resolver to confirm domain ownership, then it could issue certificates even for non-DNS names. Some exploratory work has proposed using DNSLink or reverse record mappings from ENS domains to DNS names as a bridge, where control of a DNS name linked to a .eth domain allows indirect validation and issuance. Still, this approach often collapses back into traditional DNS dependencies, partially negating the benefits of decentralization.

Until browser vendors implement native resolution for blockchain domains and support alternative PKIs or validation flows, the TLS problem for Web3 domains will remain only partially solved. The lack of HTTPS support is more than a cosmetic issue—it prevents these domains from being used securely for a range of services, including login portals, payment gateways, or sensitive communications. It also undermines user trust, as the absence of a padlock icon or the presence of browser warnings can deter users even when the site itself is technically safe.

The future likely depends on a combination of efforts: more robust gateway transparency and decentralization, standardized smart contract-based verification methods for new CAs, and eventual browser support for decentralized resolution and new trust anchors. Community-driven governance of naming protocols like ENS may also play a role in establishing standards for on-chain key registration and secure session negotiation. In the long term, the goal is to enable users to interact with Web3 domains as seamlessly and securely as they do with .com domains today—encrypted, authenticated, and decentralized, without reliance on traditional Web2 intermediaries. Until then, TLS for blockchain domains will remain a critical but incomplete piece of the decentralized web stack.

As decentralized naming systems such as Ethereum Name Service (ENS), Unstoppable Domains, and Handshake gain traction as alternatives to traditional DNS-based domains, a major unresolved issue remains the integration of Transport Layer Security (TLS) certificates. TLS is a foundational technology in web security, enabling encrypted connections and authenticating websites through the familiar padlock icon in…