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Cryptographic protocol

A security protocol is an abstract or concrete protocol that performs a security-related function and applies cryptographic methods as sequences of cryptographic primitives. A protocol describes. A sufficiently detailed protocol includes details about data structures and representations, at which point it can be used to implement multiple, interoperable versions of a program. Cryptographic protocols are used for secure application-level data transport. A cryptographic protocol incorporates at least some of these aspects: Key agreement or establishment Entity authentication Symmetric encryption and message authentication material construction Secured application-level data transport Non-repudiation methods Secret sharing methods Secure multi-party computationFor example, Transport Layer Security is a cryptographic protocol, used to secure web connections, it has an entity authentication mechanism, based on the X.509 system. These three aspects have important interconnections. Standard TLS does not have non-repudiation support.

There are other types of cryptographic protocols as well, the term itself has various readings. For instance, TLS employs what is known as the Diffie–Hellman key exchange, which although it is only a part of TLS per se, Diffie–Hellman may be seen as a complete cryptographic protocol in itself for other applications. A wide variety of cryptographic protocols go beyond the traditional goals of data confidentiality and authentication to secure a variety of other desired characteristics of computer-mediated collaboration. Blind signatures can be used for digital cash and digital credentials to prove that a person holds an attribute or right without revealing that person's identity or the identities of parties that person transacted with. Secure digital timestamping can be used to prove. Secure multiparty computation can be used to compute answers based on confidential data, so that when the protocol is complete the participants know only their own input and the answer. End-to-end auditable voting systems provide sets of desirable privacy and auditability properties for conducting e-voting.

Undeniable signatures include interactive protocols that allow the signer to prove a forgery and limit who can verify the signature. Deniable encryption augments standard encryption by making it impossible for an attacker to mathematically prove the existence of a plain text message. Digital mixes create hard-to-trace communications. Cryptographic protocols can sometimes be verified formally on an abstract level; when it is done, there is a necessity to formalize the environment in which the protocol operates in order to identify threats. This is done through the Dolev-Yao model. Logics and calculi used for formal reasoning of security protocols: Burrows–Abadi–Needham logic Dolev–Yao model π-calculus Protocol composition logic Strand spaceResearch projects and tools used for formal verification of security protocols: Automated Validation of Internet Security Protocols and Applications and follow-up project AVANTSSARConstraint Logic-based Attack Searcher Open-Source Fixed-Point Model-Checker SAT-based Model-Checker Casper CryptoVerif Cryptographic Protocol Shapes Analyzer Knowledge In Security protocolS Maude-NRL Protocol Analyzer ProVerif Scyther Tamarin Prover To formally verify a protocol it is abstracted and modelled using Alice & Bob notation.

A simple example is the following: A → B: K A, B This states that Alice A intends a message for Bob B consisting of a message X encrypted under shared key K A, B. Internet Key Exchange IPsec Kerberos Off-the-Record Messaging Point to Point Protocol Secure Shell Signal Protocol Transport Layer Security ZRTP Secure channel Security Protocols Open Repository Ermoshina, Ksenia. "End-to-End Encrypted Messaging Protocols: An Overview". In Bagnoli, Franco. Internet Science. INSCI 2016. Florence, Italy: Springer. Pp. 244–254. Doi:10.1007/978-3-319-45982-0_22. ISBN 978-3-319-45982-0. Secure protocols open repository

Alicante Tram

The Alicante Tram, trademarked as Alicante Metropolitan TRAM, operates in the Spanish city of Alicante and its surrounding area. Like other narrow gauge railways in the Valencian Community, it is run by Ferrocarrils de la Generalitat Valenciana, it was inaugurated on 15 August 2003 replacing narrow-gauge diesel trains between Alicante and El Campello. The Alicante Metropolitan Tram light rail combines different modes of rail services: a underground modern tramway through Alicante city centre, a tram-train from Alicante to Benidorm, conventional commuter rail from Benidorm to Altea, Calp and Dénia. There has been a rich history of urban rail service in Alicante; the tram service began on 13 July 1893 and the network was expanding to Mutxamel and Crevillent and San Vicente del Raspeig. The streetcars were horse-drawn. Since 1903 the trams were carried as well by the power of steam engine, leading to the disappearance of the horse-drawn trams by 1924; the electrification of tram lines began in 1923.

In 1920s and 30s the network was further expanded throughout the city and was extensively used in 1940s. In 1950s, due to high costs of electricity, trams were losing the competition against growing automobile services and by 14 November 1969 they disappeared from the streets. Thirty years on 13 March 1999 the trams were back with the inauguration of an experimental route between Plaza del Mar and Albufereta, extended to El Campello in 2003; the network comprises the following lines: L1, limited-stop service from Alicante city centre to Benidorm. In Benidorm it connects with line L9 to Dénia. L2, from the city centre to the General Hospital of Alicante, the University of Alicante and San Vicente del Raspeig. L3, stopping service from Alicante to El Campello. L4, from the city centre to a loop in Playa de San Juan district. L5, from Porta del Mar to Sangueta following the L4 loop in Playa de San Juan district. Opened in 2019, using former alignment from Porta del Mar and Sangueta, used prior to the opening of the city centre tunnel to Luceros.

L9, from Benidorm along the coast to Dénia, stopping at other important tourist towns like Altea and Calp. Services are subject to disruption due to engineering works as the line is prepared for electrification. Lines L1, L2, L3 and L4 share the city centre underground section between MARQ and the city centre Luceros station; the Mercado station on the segment was opened on 10 May 2007 and the Luceros was opened on 18 June 2010. In 2018, ridership for each line was 2,291,993 for L1, 4,397,804 for L2, 2,340,719 for L3, 1,492,224 for L4 and 531,678 for L9; the busiest stations were Luceros, Benidorm, Sant Vicent del Raspeig and El Campello. The underground section is planned to continue westward to Estació Multimodal serving the Adif station; this was delayed, but in March 2019 President of the Valencian Government Ximo Puig committed funds to progress this extension for a 2022-2023 opening. There are plans to extend the tram-train service southwards to Alicante Airport, El Altet, Gran Alacant, Santa Pola and Torrevieja.

According to the local press it seems unlikely that any of these extensions will be built in the near future due to lack of funds. Underground Stations Ground Stations Overpasses and Viaducts Tram Alicante official website Track plan of the Alicante Tram Alacant On Rails - Blog about news and tram project projects in the city of Alicante

Alfonso XII and MarĂ­a Cristina

Alfonso XII and María Cristina or Where Are You Going, Sad Man? is a 1960 Spanish historical drama film directed by Alfonso Balcázar and Guillermo Cases and starring Marga López, Vicente Parra and José Marco Davó. It is the sequel to Where Are You Going, Alfonso XII? and portrays the marriage between Alfonso XII of Spain and Maria Christina of Austria. It is similar in style to the German Sissi film series, it was popular but led to Vicente Parra's typecasting. The film's sets were designed by the art director Enrique Alarcón. Marga López as María Cristina Vicente Parra as Alfonso XII José Marco Davó as Antonio Cánovas del Castillo Tomás Blanco as Duque de Sesto María Fernanda Ladrón de Guevara Marta Padovan Ana María Custodio as Duquesa de Montpensier Francisco Arias Rafael Bardem as Doctor Federico Rubio y Galí Rosita Yarza Mario Morales María Dolores Cabo Antonio Jiménez Escribano Felip Peña Manuel Insúa José Sepúlveda as Damián Josefina Serratosa José Morales Consuelo de Nieva Carolina Jiménez Mario Bustos José Vidal Salvador Muñoz Mario Beut Rafael Calvo Gonzalo Medel Amalia Sánchez Ariño Ramón Hernández Marta Novar Alejo del Peral Carmen Aroca Juan Eulate as Novaleches Camino Delgado Julia Pachelo José Cuenca Carmen Lozano Lolita de Málaga Manuel Ausensi Miguel Aguerri Mira, Alberto.

Historical Dictionary of Spanish Cinema. Scarecrow Press, 2010. Alfonso XII and María Cristina on IMDb

Open Water 2: Adrift

Open Water 2: Adrift is a 2006 psychological horror film filmed in Malta, starring Eric Dane, Susan May Pratt, Richard Speight, Jr. Niklaus Lange, Ali Hillis, Cameron Richardson. Promotional posters claim. Despite the title, the film has no connection to Open Water and the script had been written before it was theatrically released. After Open Water became a success, Adrift was produced and the name was changed to Open Water 2: Adrift in some countries to capitalize on the success of the earlier film. A group of friends, James, Lauren and Dan's new girlfriend, Michelle, go for a weekend cruise on Dan's new yacht. Amy and James bring their infant daughter, Sarah. Most of the friends decide to jump into the water for a swim, except Amy and Dan, who are still on board with the baby. Amy is tending to her baby and puts her down for a nap. Amy puts her life jacket, which she refuses to take off while on board, back on. Amy is hydrophobic after a childhood traumatic event - as a young child, while swimming with her father, he tragically drowned.

Amy and Dan talk about her fear, but while he is talking he scoops her into his arms, as she screams, jumps into the water with her. However, it turns out that nobody had thought to lower the ramp steps before swimming, leaving them unable to re-board the ship. Now everyone is trapped in the water with only two masks, a dive knife, Amy's life vest, a toy dolphin float. Despite their efforts, the side of the yacht is too smooth to climb and the deck is too high to reach, they soon see a boat of teenagers heading towards them. The group tries to grab their attention, but the teenagers think that they are just greeting them, sail off. Next, the group tries using a ringing phone, in one of the guys' pockets; the phone is soaking, as he tries to answer it, they hear the voices of some well wishers, but are unable to respond. The phone goes dead; the guy angrily throws the phone into the ocean. Michelle screams and tries to retrieve it, they are left to tread water disconsolately. The group resorts to removing and using their bathing suits to make a rope.

After a couple of attempts they manage to get one end of the rope wrapped around a railing. Instead of having the lightest person climb up, the heavier Zach attempts to climb, he pulls himself up and his fingers brush the gunwale but the makeshift rope rips apart as he is too heavy. The group are now naked and have only a partial swim suit rope. Meanwhile, James goes underwater, messes with the prop, in an attempt to remove it and use it, but he drops the knife, he swims down after it and manages to catch it desperately panicking under water, tries to swim for the surface. As he swims back up he crashes into the bottom of the boat, is knocked unconscious, he resurfaces blood trickling out his head with an obvious skull fracture. Zach starts stabbing the boat to climb back up. Dan tries to stop him. Fearing that sharks will be attracted by the blood, the now hysterical Michelle begins to swim away, but sinks underwater. Dan sees her lifeless body drifting underwater, he dives after her, but he can't reach her, her body disappears into the depths.

After some time, Zach dies from blood loss in Lauren's arms. She reluctantly lets go of his body. Out of guilt, Dan admits. After much waiting, Lauren says she refuses to die treading water and attempts to swim back to shore to find help, her fate after this is unknown. That night, during a rainstorm, James dies from his head injury. Dan unsuccessfully searches underwater for the knife, he slams his mask on the hull in frustration and the lens pops out. Remembering Zach's attempt with the knife, Dan uses it to wedge in the crevice of the side door for the ladder, giving him a handhold. Amy climbs over his shoulders stepping onto his hand wrapped around the lens, causing him to scream as his hand bleeds more and manages to grab the gunwale and pull herself back on board. Once on board, she tends to her baby, Sarah. Amy notices Dan swimming away to drown out of guilt, she jumps back in to save him, reminding her of when she attempted to save her father in the same manner, at a young age. The next morning, a fishing boat approaches the yacht, notices the lowered ladder and life ring still floating in the water - no one had pulled them in.

The yacht appears empty except for the sound of Sarah crying on the lower deck. The film cuts to Amy looking around appearing heartbroken. Dan is shown lying face down on the boat with a towel covering his lower half either sleeping or dead. Susan May Pratt as Amy Alexandra Raach as young Amy Eric Dane as Dan Richard Speight Jr. as James Niklaus Lange as Zach Ali Hillis as Lauren Cameron Richardson as Michelle Wolfgang Raach as Amy's father Open Water 2: Adrift received mixed reviews from critics. Review aggregate website Rotten Tomatoes gave the film an overall score of 40% based on 10 reviews. In the United Kingdom, the film opened at 327 theaters, grossing £337,474, averaging £1,033 per theater. 123 theaters dropped the film for the second weekend, its ticket sales declined by 75 percent, making £85,541, averaging £419. During the third weekend, the film's sales tumbled 90 percent after 183 more theaters dropped it, making £8,896; the fourth weekend brought an addit

Paul Scott (comics)

Paul Scott, sometimes known as Paul von Scott, is a British comics writer and games designer, active in the British small press comics scene. Paul attended the University of Birmingham, he produces Solar Wind as well Big War Comic, Sunny For Girls and Warlock Holmes. In addition he has written for various other small press publications including FutureQuake, Something Wicked, The End Is Nigh and Starscape, he now runs Midlam Miniatures. 2004: Won "Best British Independent Comic" National Comics Award for Solar Wind. 2006: Nominated for "Best British Black and White Comic" Eagle Award for Solar Wind Midlam Miniatures website Official website Interview at 2000AD Review Omnvistascope Model 1 review, Comics Bulletin