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TETRA Experience 2006

TETRA Experience 2006. Sao Paulo July 18 th 2006. TETRA Security Encryption and Management. Ramón Montañez. Agenda. Security threats TETRA security features Authentication Air interface Encryption End to End encryption Practical security measures.

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TETRA Experience 2006

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  1. TETRA Experience 2006 Sao Paulo July 18th 2006

  2. TETRA Security Encryption and Management Ramón Montañez

  3. Agenda • Security threats • TETRA security features • Authentication • Air interface Encryption • End to End encryption • Practical security measures TETRA Experience - Brazil

  4. What we want to achieve with Security • Confidentiality • No one can eavesdrop on what we are saying • Integrity • The information gets there completely intact • Availability • Communications are possible where and when they are needed • Authenticity • The people we are talking to are the right people • The wrong people can’t try and join us TETRA Experience - Brazil

  5. Threats to communication and the threats to security • Message related threats • interception, eavesdropping, masquerading, replay, manipulation of data • User related threats • traffic analysis, observability of user behavior • System related threats • denial of service, jamming, unauthorized use of resources TETRA Experience - Brazil

  6. Network Security • IT security is vital in TETRA networks • Gateways are particularly vulnerable. • Operating staff need vetting • Firewalls required at access points to the network TETRA Experience - Brazil

  7. Dispatcher Base Station Base Station Infrastructure “ “ ????” ????” “ XYZ” 1. Authentication 1. Authentication 3. End - to - End Encryption 3. End - to - End Encryption 2. Air Interface Encryption 2. Air Interface Encryption Key Definitions of TETRA Security • Authentication - ensures only valid subscriber units have access to the system and subscribers will only try and access the authorized system • Air Interface Encryption – protects all signaling, identity and traffic across the radio link • End-to-End Encryption protects information as it passes through the system TETRA Experience - Brazil

  8. Authentication • Used to ensure that terminal isgenuine and allowed on network. • Mutual authentication ensures that in addition to verifying the terminal, the SwMI can be trusted. • Authentication requires both SwMI and terminal have proof of secret key. • Successful authentication permits further security related functions to be downloaded. TETRA Experience - Brazil

  9. Authentication Authentication Center • Authentication provides proof identity of all radios attempting use of the network • Radio can authenticate the network in turn, protects against ‘fake base stations’ etc • A session key system from a central authentication centre allows highly secure key storage • Secret key need never be exposed • Authentication process derives air interface key (TETRA standard) – automatic key changing! Challenge Session keys Calculated Response Switch Secret keys Mutual Challenge MS Calculated Response TETRA Experience - Brazil

  10. Radio Security Provisioning And Key Storage • TETRA MoU SFPG Recommendation 01 provides a standardized format for importing authentication and other air interface encryption keys • Use of Recommendation 01 files will allow multi vendor terminal supply • Separation of logical key programming step from factory can allow all keys to be loaded in country • Meets national security requirements SCK, GCK etc… AuC Standardized format Imports key material from any vendor TEI Factory TETRA SwMI TEI Key Programming K K, TEI TETRA Experience - Brazil

  11. What is Air Interface Encryption? • First level encryption used to protect information over the Air Interface • Typically software implementation • Protects almost everything – speech, data, signaling, identities… • Class Encryption OTAR Authentication • 1 No No Optional • 2 Static key Optional Optional • 3 Dynamic key Mandatory Mandatory TETRA Experience - Brazil

  12. The air interface was considered vulnerable. • Air Interface encryption was designed to make the air interface comparably as secure as the fixed line connection Fixed Links Air Interface Encryption Clear Air Interface! The purpose of Air Interface Encryption • Network fixed links are considered difficult to intercept. Operational Information TETRA Experience - Brazil

  13. Air Interface traffic keys • Four traffic keys are used in class 3 systems:- • Derived cipher Key (DCK) • derived from authentication process used for protecting uplink, one to one calls • Common Cipher Key (CCK) • protects downlink group calls and ITSI on initial registration • Group Cipher Key (GCK) • Provides crypto separation, combined with CCK • Static Cipher Key (SCK) • Used for protecting DMO and TMO fallback mode TETRA Experience - Brazil

  14. Standard air interface algorithms • TEA1 and TEA4 • General use including public safety • TEA2 • Europe public safety and military organizations only. • TEA3 • For use by public safety and military organizations outside of Europe. TETRA Experience - Brazil

  15. Over The Air Re-keying (OTAR) • Populations of terminals tend to be large and spread over wide areas so the only practical way to change encryption keys is by OTAR • This is done securely by using a derived cipher key or a session key to wrap the downloaded key • The security functionality is transparent to the user as the network provider would normally be responsible for OTAR and management of AI keys TETRA Experience - Brazil

  16. End to end encryption in TETRA • ETSI Project TETRA provides standardized support for end to end Encryption • ETSI EN302109 contains specific end to end specification • Ensures TETRA provides a standard alternative to proprietary offerings and technologies • Ensures compatibility between infrastructures and terminals • Many organizations want their own algorithm • Confidence in strength • Better control over distribution • TETRA MoU – Security and fraud Protection Group (SFPG) • Provides detailed recommendation on how to implement end to end encryption in TETRA • The result – Standardization and compatibility, with choice of algorithm • A big strength of TETRA TETRA Experience - Brazil

  17. Standard end to end encryption algorithms • There are no ‘standard’ algorithms defined by SFPG but: • IDEA was defined as a good candidate 64 bit block cipher algorithm for use with TETRA and test data and an example implementation was produced • AES128 (Rijndael) was defined as a good candidate 128 bit block cipher algorithm for use with TETRA and test data and an example implementation was produced • Both algorithms have proved popular with public safety organizations and give a good level of security assurance to sensitive data TETRA Experience - Brazil

  18. End To End Encryption ‘Standardization’ • TETRA MoU SFPG Recommendation 02 • Framework for end to end encryption • Recommended synchronization method for speech calls • Protocol for Over The Air Keying • Sample implementations including algorithm mode and key encryption • DOES NOT specify implementation – can be implemented with module, software, SIM card etc.. • DOES NOT provide module interface specification TETRA Experience - Brazil

  19. Related Recommendations • TETRA MoU SFPG Recommendation 01 • Key transfer specification • Currently being updated to include end to end encryption key import formats • TETRA MoU SFPG Recommendation 07 • Short data service encryption • TETRA MoU SFPG Recommendation 08 • Framework for dividing encryption functionality between a SIM (smartcard) and a radio • No defined bit level interface (export control issue) • TETRA MoU SFPG Recommendation 11 • IP Packet data encryption • Work in process • Will provide a suitable means for high security packet data encryption, with commonality with voice encryption TETRA Experience - Brazil

  20. TETRA Network Other Network Other Network Other Network Implementing TETRA security • TETRA security measures are by no means the complete picture • How well they are implemented – and how the implementation is evaluated is critical • The rest of the network – what else connects to TETRA – is equally important • The operational process and procedures equally provide countermeasures to the threats Link Landline TETRA Experience - Brazil

  21. Implementation considerations – Air Interface Encryption • AIE should provide security equivalent to the fixed network • There are several issues of trust here • Do I trust that the AIE has been implemented properly? • Does AIE always operate (during registration, in fallback modes etc)? • Do I trust the way that the network (or radio) stores keys? • Do I trust the fixed network itself or can someone break in? • A strong AIE implementation and an evaluated network can provide essential protection of information • An untested implementation and network may need reinforcing, for example with end to end encryption TETRA Experience - Brazil

  22. Benefits of end to end encryption in combination with Air Interface encryption • Air interface (AI) encryption alone and end to end encryption alone both have their limitations • For most users AI security measures are completely adequate • Where either the network is untrusted, or the data is extremely sensitive then end to end encryption may be used in addition as a overlay. • Brings the benefit of encrypting addresses and signalling as well as user data across the Air Interface and confidentiality right across the network TETRA Experience - Brazil

  23. Disabling of terminals • Vital to ensure the reduction of risk of threats to system by stolen and lost terminals • Relies on the integrity of the users to report losses quickly and accurately. • Disabling may be either temporary or permanent • Disabling stops the terminal working as a radio and: • Permanent disabling removes all keys including (k) • Temporary disabling removes all traffic keys but allows ambience listening • The network or application must be able to remember disable commands to terminals that are not live on the network at the time of the original command being sent. TETRA Experience - Brazil

  24. Useful Recommendations • TETRA MoU SFPG Recommendation 03 – TETRA threat analysis • Gives an idea of possible threats and countermeasures against a radio system • TETRA MoU SFPG Recommendation 04 – Implementing TETRA security features • Provides guidance on how to design and configure a TETRA system • Both documents are restricted access requiring Non Disclosure Agreement with SFPG TETRA Experience - Brazil

  25. Assuring your security solution • There are two important steps in assuring the security of the solution: Evaluation and Accreditation • Evaluation of solutions should be by a trusted independent body • Technical analysis of design and implementation • Accreditation is the continual assessment of risks • Assessment of threats vs. solutions • Procedural and technical solutions • Should be undertaken by end user representative and/or their government national security organization TETRA Experience - Brazil

  26. Maximizing cost effectiveness • Evaluation can be extremely expensive – how to get best value for money? • Establish the requirements in advance • as far as they are known – security is always a changing requirement! • Look for suppliers with track record and reputation • Look for validations of an equivalent solution elsewhere • Consider expert help on processes and procedures TETRA Experience - Brazil

  27. What security level do you want? • TETRA Class 1 • TETRA Class 2 • TETRA Class 3 • TETRA w/ E2E algorithm on Smart Card • TETRA w/ E2E SW algorithm in radio • TETRA w/ E2E hardware solution TETRA is @ your Service TETRA Experience - Brazil

  28. www.Tetramou.comwww.ETSI.orgwww.Motorola.com/TetraRamon.Montanez@motorola.comwww.Tetramou.comwww.ETSI.orgwww.Motorola.com/TetraRamon.Montanez@motorola.com Thank You TETRA Experience - Brazil

  29. TETRA Experience 2006 Sao Paulo July 18th 2006

  30. TETRA Data Services & Applications Ole Arrhenius

  31. Contents • Basic data services in TETRA • The concern about data speed • TETRA data applications, examples • Wireless Application Protocol, WAP • Towards higher data speeds • Conclusions

  32. Basic data services in TETRA 4 channels • Status messages • efficient, real time • Short Data Service, SDS • text messaging + application platform • IP packet data • advanced applications, opens the world of Intranet and Internet connectivity • Circuit mode data • for specialized applications, rarely used 36 kbits/s gross bit rate 2 1 3 4 Carrier

  33. Status messages • Data sent as 16 bit numeric values • 32768 values free for use, the rest reserved for system use • Converted into text in the receiving terminal or workstation • Fast and efficient • Easy to use • Sent over control channel, do not load traffic channels

  34. MM05 11:28 p12553: VIPs arriving in 5 minutes at gate 23, prepare security and transport. OK Short Data Service Hello, I will be back in the ioffice in 15 minutes. I will call you then. John OK • Four SDS-types specified by TETRA standard: SDS-1, SDS-2, SDS-3 and SDS-4 TL • SDS-1, -2 and -3 are fixed length (16, 32, 64 bits) • SDS-4 TL is variable length (max 1278 bits). Protocol identifier defines how SDS-4 is used, most typical use is text messaging (140/160 chars) and AVL • Data sent over control channel or traffic channel (simultaneous voice and data) • Text entry using the keypad of the phone, single device for voice and data

  35. IP-packet data • Similar to the GPRS service in GSM networks • Enables advanced data applications • Enables Intranet and Internet connectivity • Excellent application platform • Uses traffic channel, single slot or multiple time slots

  36. TETRA data services enable a wide range of applications • Database access • Image communications • Intranet/internet access • Reporting • e-mail, calendar • Workforce management • CC&C system integration • File transmission • Information push, alarm distribution • Information pull • Control and monitoring, telemetry

  37. TETRA fullfils 95% of daily data needs Fundamental daily services 95% Complementing non-criticalservices 5% Complementary wireless data services can be used to complement non-critical data services, if necessary

  38. The concern of data speed • Single slot IP packet data provides approximately 3 … 4 kbps payload • Multislot data increases performance but has side effects • Increased power consumption in handsets • Decreases voice capacity • Robust basic data services more important than extreme speeds especially in public safety • Majority of daily data services consist of low data volume database queries in the range of 0.5 … 10 kB per transaction • Smart applications are more important than the raw data speed, bloated applications will eat available bandwidth, no matter how much bandwidth is available

  39. The concern of data speed, example Optimized for handportable radio’s screen 7 kB • Original photo image taken with a digital camera. Original size is 1600x1200 and file size 1MByte • Pixel size of a TETRA handheld terminal typically 100 x 130 pixels • Compression and optimization for 100x130 pixel screen shrinks the 1MByte image into 7 kilobytes 100 x 130 x 16 (colour) = 26 kBytes With further optimisation and compression from 26 kB to 7 kB

  40. Example of an integrated, smart application • Police field command application using AVL, on-board databases, status messaging, text messages and IP packet data • Minimizes over-the-air data, yet very graphics intensive and informative

  41. On screen AVL map with touch screen action buttons …

  42. F1Show F2Report/His F3Status F4Maps/AVL F5Messages F6 Equipment F7Forms/En POKE/K1 F8Setup 812 Free On the way 813 At scene Transport ZOOM+ Not in car 811 ZOOM-- Car chase 814 F9MOB Off-duty

  43. Send only the necessary information over the air • Keep high volume, ‘static’ data (maps, images, floorplans of buildings) in onboard databases • Update static data at the station using fixed LAN or WLAN • Over the air information is typically low volume: • Location information • Status of field units • Text messaging • Compressed images

  44. More examples of applications using TETRA data services

  45. Automatic Vehicle/Person Location, AVL / APL • Integrated GPS in new terminals • Position of every unit in real time • Location shown on GIS at Command and control room • TETRA SDS or TETRA IP can be used to deliver location information • New ETSI LIP standard for compact SDS location information, 76 bits instead of about 200 bits

  46. Image communication • ”One picture paints thousand words” • TETRA IP one slot packet data is sufficient for image transmission • Image compression technologies reduce data volumes for fast transmission, e.g. JPEG2000 • Retrieve images from a database (pull) • Send images from command and control centre (push) • Increases efficiency and officer safety

  47. Wireless Application Protocol (WAP) • Specified to create a global protocol to work across differing wireless network technologies • WAP offers bearer independence • Allows applications developed to work across TETRA and GSM and GPRS • Optimised for the constraints of handheld devices WAP Server Application Portal 2. Locate 3. Mail 4. Report 5. Search Link Menu TETRA

  48. What about the future ?

  49. TETRA High Speed Data • TETRA high speed data is part of TETRA 2 standardization • TETRA HSD will complement the current TETRA services with higher data speeds • User experience comparable to GPRS/EDGE • Very spectrum-efficient • Adapts its speed (modulation) when necessary

  50. Development continues Next … TETRA High Speed Data Evolution Java Multi-slot packet data Situationawareness Integrated GPS Colours Advanced locationapplications Imagecommunication Time

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