Complexity of the basic methods
{"Image DocumentName": "Complexity of the basic methods", "Image ImageDescription": "unobservability of neighboring lines and stations as well as digital signal regeneration. RING-network. DC-network. MIX-network. attacker model. physically limited. computationally restricted w.r.t. service delivery. computationally restricted. cryptographically strong. well analyzed. not even well analyzed asymmetric encryption systems are known which are secure against adaptive active attacks. expense. per user. O(n) ( \uf0b3 ) transmission. O(k\u2022n) key. O(k), practically: \u2248 1 transmission on the last mile. ... in the core network. O(k2), practically: \u2248 k. now compare methods\u2026 with respect to security (attacker model!) effort (expense) ring network: attacker is physicasl limited \u2013 otherwise InfoTheoSecure\u2026 expense: for sending a message: linear with number of users \u2013 one time aroudn the ring\u2026 if not brodcast: roughly n/2 (i.e. recipient replaces message to be returned to sender) BTW: red color: unhappy \u2013 not really good \uf0e0 linear grow: too much! DC-Net: info secure. BTW: green: real good! \uf04a (restriction: attacker can open traps \uf0e0 break service delivery\u2026) BUT: Very expensive \uf0e0 long keys! remeber solution: PRNG \uf0e0 computational secure\u2026 sending: o(n) for sending! also much expense for key distribution\u2026 Mix: down side: computation restricted because of asym crypto. but even asym crypto might not as good as it should be\u2026. rember the attack: RSA was not broken!!! \u2013only related ciphertext there used\u2026 expense: message grows slowly with every mix. very good! last mile: two user \uf0e0 that is that users pay for! note: user sends only to first mix! recevies only from last! problem in the core network: each mix retransmitts messages \uf0e0 8ok^2) \uf0e0 o(k) (because of small grow) \uf0e0 still expense need to be payed by user\u2026 security: dc-net. practicability: mix net (but crpyto might be a problem \u2013 but in practice much more problematic: dummy traffic!) note: this is there engeniiering starts. (next slide) n. 2. n. 2. n = number of users. k = connectedness key graph of DC-networks respectively number of MIXes.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}