Telnic is a limited liability company incorporated in England with registration number 3555437. The company has its head office at 37 Percy Street, London W1T 2DJ.

Telnic's sole purpose is to act as the Registry Operator and Sponsoring Organization for .tel, a new sponsored Top Level Domain awarded on May 30th 2006 by ICANN, the Internet Corporation for Assigned Names and Numbers.

The innovative .tel technology presented by Telnic Ltd. allows using the DNS as a data store for key-value pairs, not just IP addresses. The primary use of .tel is to store contact information, such as phone numbers, IM IDs, addresses, and keywords, in the form of NAPTR and text records.

TelHosting Software

The cornerstone of the .tel technology is the TelHosting software platform that handles publication of data directly into the DNS and the related privacy and security settings. The .tel allows for encryption of stored data and their decryption with a public key provided to select users.

The purpose of the TelHosting Software is to create and maintain the DNS zones as well as to publish these zones on the name servers. The system is backed by an SQL database and is designed to inter-operate with a number of database and name server implementations. The platform can be easily integrated with existing registrar infrastructures to provide support for .tel domain names.

Client applications that manipulate .tel domains interact with the TelHosting platform via a standardized SOAP API, which can be logically divided into the 'read' API responsible for looking up .tel domains in the database, and the 'write' API for editing data for a specific .tel domain. The TelHosting Software also allows managing contact data via a web interface.

TelHosting Software is an open-source Java* application developed by Telnic Ltd. to enable creation and publication of zones in the .tel DNS. The system is backed by an SQL database and is designed to inter-operate with a number of database and name server implementations. The platform can be easily integrated with existing registrar infrastructures to provide support for .tel domain names.

TelHosting Providers can install this application and integrate it into their existing infrastructure, or can develop their own platform for .tel name service provisioning. The open-source version of TelHosting Software will be soon made available.

TelHosting

TelHosting is the process of creating .tel DNS zones and their publication on designated servers. Only companies accredited by Telnic Ltd., TelHosting Providers, can perform these actions. The TelHosting Provider operates name servers to resolve .tel domains and TelHosting Software to create, maintain, and publish zones on these name servers. The software also handles privacy and security settings related to encryption and decryption of stored data.

Client applications that manipulate .tel domains interact with the TelHosting platform via a standardized SOAP API, which can be logically divided into the 'read' API responsible for looking up .tel domains in the database, and the 'write' API for editing data for a specific .tel domain. The TelHosting Software also allows managing contact data via a web interface. For a description of the TelHosting Provider role, see Technical Requirements for TelHosting.

Record Types

Compared to traditional top-level domains, the .tel DNS uses a different set of record types. User-specified Address and CNAME records are prohibited, and the following are allowed:

• TXT - text record for storing keywords and other freeform text
• LOC - location records containing latitude, longitude and altitude data
• NAPTR (Naming Authority Pointer Record) - a record holding a URL and an Enumservice that indicates the type of URL information, such as email or phone number; NAPTRs can be
  • Terminal - holding contact information, such as phone number, Skype ID, etc.
  • Non-terminal - holding a pointer to another domain or subdomain, which may hold more data

NAPTR records are powerful resource records with a number of important advantages, such as small package size, high-speed propagation and real-time updating. NAPTR keys can support any Enumservice type, including voice:tel or im:x-skype or a pointer to a subdomain or another domain. In addition, NAPTR records can be ordered and labeled. However, support for NAPTRs is not yet common and requires extra effort; to make working with .tel domains easy, the TelHosting Software already provides this support.

Wikipedia gives a more detailed description of NAPTRs, and RFC3403 contains the specification of this resource record. For more information on NAPTR usage in .tel, please read the whitepaper NAPTR Records in .tel.

Privacy

The .tel platform includes a friending mechanism for controlling access to published contact information. In fact, any NAPTR data can be secured and made private to any friend. For example, if Alice owns alice.tel and she has friends Bob and Charlie, she could make her office telephone number public, restrict her email address to be shown only to Bob and Charlie, and make her home phone number viewable only by Bob.

Private data is encrypted and stored inside NAPTR records of type "x-crypto". The X-Crypto NAPTR has been designed not to break IANA ENUM service type formats and abide by the IETF “ENUM Experiences” document.

The process to secure data consists of three procedures that are performed by the encryption routines:

1. The plaintext is processed with PKCS#1.5 or OAEP padding to provide extra protection against attack and create a standard block size (in this case 128 bytes).
2. The plaintext is 1024-bit encrypted with the reader's public key to obtain 128 bytes of binary data.
3. The binary data is Base 64 encoded so that the encrypted data can be stored in a NAPTR record without containing special characters.

Note: We do NOT recommend storing sensitive personal information such as credit card numbers inside a .tel domain. This is not the purpose of the .tel.

The public-private key pair technique can be used for secure data exchange bypassing the “official” .tel friending system. All you need to know is how to decrypt your friend’s encrypted data.

For more information on the .tel security model, please read our whitepaper Protecting .tel Contact Data.