Ubiquitous and Secure Networks and Services Ubiquitous Systems

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Ubiquitous and Secure Networks and Services Redes y Servicios Ubicuos y Seguros Unit 5: Ubiquitous Systems Security Lourdes López Santidrián llopez@diatel. upm. es, lourdes. lopez@upm. es © Lourdes López Santidrián

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security UNIT 5: Ubiquitous Systems Security VULNERABILITIES OF UBIQUITOUS NETWORKS AND SERVICES © Lourdes López Santidrián 2

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Why WSN are vulnerable against attacks? q The sensor nodes are constrained by: m. Battery life. m. Computational capabilities. m. Memory. m. Communication band. q Is easy to physically access to nodes: m. Human or machine can reprogram them. m. Human or machine can destroy them. q The communication channel is public. q It is difficult to monitor and control the distributed elements. © Lourdes López Santidrián 3

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Threats q Common Attacks: m. Eavesdropping (passive). m. Data injection (active). m. Message modification (active). m. Message replay (active). q Denial of Service Attacks (Do. S): m. Jamming: target the communication channel. m. Power exhaustion: target the nodes. q Node Compromise: m. An attacker can read or modify the internal memory of a node. © Lourdes López Santidrián 4

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Threats q Side-channel Attacks: m. Monitoring of the nodes’ physical properties. m. Acquisition of security credentials (secret keys). q Impersonation Attacks: m. Sybil attack (creation of fake identities). m. Replication attack (creation of duplicate identities). q Protocol-specific Attacks: m. Routing protocols. ØSpoofed Routing Information. ØHELLO Flood Attack. m. Aggregation protocols: falsifying information. m. Time synchronization protocols. © Lourdes López Santidrián 5

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Services q Confidentiality m. Only the desired recipients can understand the message. m. May be not mandatory. q Integrity m. If the data produced and sent over the network are altered, the receiver will have a proof. m. In most cases it is a mandatory feature. © Lourdes López Santidrián 6

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Services q Authentication m. A receiver can verify that the data is really sent by the claimed sender. m. It is mandatory if the network needs a barrier between external and internal members. q Authorization m. It states that only authorized entities can be able to perform certain operations. q Availability m. The users of a WSN must be capable of accessing its services whenever they need them. © Lourdes López Santidrián 7

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Services q Freshness m. The data produced by the WSN must be recent q Forward and Backward Secrecy m. Forward secrecy: where a node should not be able to read any future messages after it leaves the network m. Backward secrecy: where a node is not able to read a previously transmitted message. q Self-organization m. Nodes must be independent and flexible in order to react against problems. © Lourdes López Santidrián 8

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Services q Auditing m. The elements of a WSN must be able to store any events that occur inside the network. q Non-repudiation m. A node cannot deny sending a message, or a recipient cannot deny the reception of a message. m. Evidence that the message was sent is necessary. q Privacy and Anonymity m. The identity of the nodes should be hidden or protected. © Lourdes López Santidrián 9

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security UNIT 5: Ubiquitous Systems Security CRYPTOGRAPHIC MECHANISMS AS THE BASIS OF THE SECURITY © Lourdes López Santidrián 10

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Secret/Symmetric Key Cryptography c = EK (m) m c m DK (c) = DK (EK (m)) K K A B © Lourdes López Santidrián Confidentiality Integrity 11

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Secret/Symmetric Key Algorithms Time CPU Power Algorithm (ms) Cycles (μJ) Skip. Jack 2, 16 (3) 15. 925, 2 (3) 51, 4 (3) 19 (4) RC 5 1, 50 (2) 11. 059, 2 (1) 36, 00 (1) 16 (3) RC 6 10, 78 (5) 79. 478, 7 (5) 258, 72 (5) 16 (3) TEA 2, 56 (4) 18. 874, 4 (4) 61, 44 (4) 15, 5 (1) XTEA 1, 45 (1) 12. 450, 2 (2) 40, 7 (2) 15, 5 (1) 608, 00 (6) 4. 482. 662, 4 (6) 14. 592, 00 (6) 31 (6) DES © Lourdes López Santidrián ROM Memory (Kb) 12

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Public/Asymmetric Key Cryptography c = KPB(m) m c m KSB (c) = KSB (KPB (m)) KSA KSB A © Lourdes López Santidrián KPA KPB …. B Confidentiality Authentication Key agreement 13

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Public/Asymmetric Key Algorithm Elliptic Curve Cryptography (ECC) q Tiny. ECC m. ECC-based signature generation and verification (ECDSA). m. Encryption and decryption (ECIES). m. Key Agreement (ECDH). © Lourdes López Santidrián 14

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Hash Functions q One-way functions: m. If we have m (any size) and H hash function (digital fingerprint): Øh = H(m) with fix size. m. It is almost impossible calculate m from H-1(h) q Can be used to build: m Message Integrity Code (MIC). m Message Authentication Code (MAC). ØAuthentication. ØIntegrity. © Lourdes López Santidrián 15

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security UNIT 5: Ubiquitous Systems Security INTRUSION DETECTION © Lourdes López Santidrián 16

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Definition of Intrusion Detection q. Anomaly detection: m. Analyze the network or system and infer what is “normal” from the analysis. m. Application of statistical or heuristic measures. m. If an event isn’t “normal” generate an alert q. Misuse detection: m. Know what an “attack” is. m. Detection of “attacks”. © Lourdes López Santidrián 17

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security ID Components for WSN q. Neighbor monitoring m. Watchdog. q. Data fusion m. Local: neighboring nodes. m. Global: overlapping areas. q. Topology discovery. q. Route tracing. q. History. © Lourdes López Santidrián 18

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security UNIT 5: Ubiquitous Systems Security SECURITY MANAGEMENT © Lourdes López Santidrián 19

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security Key Management q Key Management Systems (KMS): m. Creation. m. Distribution. m. Maintenance of secret keys. q IEEE 802. 15. 4 does not specify how secret keys should be exchanged. q A key-exchange protocol is needed: m“Key pool” Framework. m. Mathematical Framework. m. Negotiation Framework. m. Public Key Framework. © Lourdes López Santidrián 20

Ubiquitous and Secure Networks and Services: Ubiquitous Systems Security at WSN Standards q IEEE 802. 15. 4 -2066 security: m. Confidentiality: HW support for AES-128. m. Integrity: MIC or MAC. m. Received Message Authentication: Access Control List (ACL). q Zig. Bee 2006 and 2007 security: m. Standard Security. m. Confidentiality and Authentication at NWK and APS levels. m“All nodes on the network trust each other”. q Zig. Bee PRO security: m. High Security. m. Master key for Symmetric-Key-Exchange. © Lourdes López Santidrián 21