The World Trade Center site referred to as "Ground Zero" or "the Pile" after the September 11 attacks, is a 14.6-acre area in Lower Manhattan in New York City. The site is bounded by Vesey Street to the north, the West Side Highway to the west, Liberty Street to the south, Church Street to the east; the Port Authority owns the site's land. The previous World Trade Center complex stood on the site until it was destroyed in the September 11 attacks; the Port Authority of New York and New Jersey, Silverstein Properties, the Lower Manhattan Development Corporation have overseen the reconstruction of the site as part of the new World Trade Center, following a master plan by Studio Daniel Libeskind. Developer Larry Silverstein holds the lease to retail and office space in four of the site's buildings; the western portion of the World Trade Center site was under the Hudson River, with the shoreline in the vicinity of Greenwich Street. On this shoreline close to the intersection of Greenwich Street and the former Dey Street, Dutch explorer Adriaen Block's ship, the Tyger, burned to the waterline in November 1613, stranding Block and his crew and forcing them to overwinter on the island.

The remains of the ship were buried under landfill when the shoreline was extended starting in 1797, were discovered during excavation work in 1916. The remains of another ship from the eighteenth century were found in 2010 during excavation work at the site; the ship, believed to be a Hudson River sloop, was found just south of where the Twin Towers used to stand, about 20 feet below the surface. The area, cleared for construction of the original World Trade Center complex was occupied by various electronics stores in what was called Radio Row; these streets and stores were demolished in the 1960s to make way for the World Trade Center. At the time of their completion the "Twin Towers"—the original 1 World Trade Center, at 1,368 ft, 2 World Trade Center —were the tallest buildings in the world; the other buildings in the complex included the Marriott World Trade Center, 4 WTC, 5 WTC, 6 WTC, 7 WTC. All of these buildings were built with a construction cost of $400 million; the complex was located in New York City's Financial District and contained 13,400,000 square feet of office space.

The World Trade Center experienced a fire on February 13, 1975, a bombing on February 26, 1993 and a robbery on January 14, 1998. In 1998, the Port Authority decided to privatize the World Trade Center, leasing the buildings to a private company to manage, awarded the lease to Silverstein Properties in July 2001. On the morning of September 11, 2001, Islamic terrorists affiliated with Al-Qaeda hijacked American Airlines Flight 11 and United Airlines Flight 175, both which were en route to Los Angeles, intentionally crashed them into the two main towers of the World Trade Center; the towers collapsed within two hours of the collisions. 2,606 people, including 2,192 civilians, 343 firefighters, 71 law enforcement officers who were in the towers and in the surrounding area died in the attacks, as well as 147 civilians and the 10 hijackers aboard the two airliners. After the collapse of the World Trade Center, hospital workers and law enforcement officers began referring to the World Trade Center site as "Ground Zero".

The collapse of the towers spread dust across New York City and left hundreds of thousands of tons of debris at the site. To organize the cleanup and search for survivors and for human remains, the New York City Fire Department divided the disaster site into four sectors, each headed by its own chief. Cleanup workers trucked most of the building materials and debris from Ground Zero to Fresh Kills Landfill in Staten Island; some people, such as those affiliated with World Trade Center Families for Proper Burial, were worried that human remains might have been inadvertently transported to the landfill. According to NIST, when WTC 1 collapsed, falling debris struck 7 World Trade Center and ignited fires on multiple floors; the uncontrolled fires led to the progressive collapse of the structure. Shortly after the attacks, the surrounding buildings were fitted with red mesh to prevent further damage. In November 2001, the remaining portions of Building 4 were leveled. In December 2001, a temporary viewing platform at Fulton Street, between Church Street and Broadway, was opened to the public.

That month, the last standing perimeter columns from the North Tower and the last remaining portions of Building 6 were removed. Early estimates suggested that debris removal would take a year, but cleanup ended in May 2002, under budget and without a single serious injury; the Winter Garden Atrium was reopened to the public on September 17, 2002, the first major structure to be restored following the attacks. Starting March 11, 2002, eighty-eight searchlights were installed and arranged to form two beams of light shooting straight up into the sky; this was called the Tribute in Light, was lit every day at dusk until April 14, 2002. After that, the lights were lit on the two-year anniversary of the attack and have been lit on each subsequent September 11 since then. In February 2005, the New York City Medical Examiner's office ended its process of identifying human remains at the site. In August 2008, New York City firefighters donated a cross made of steel from the World Trade Center to the Shanksville Volunteer Fire Company.

The beam, mounted atop a platform shaped like the Pentagon, was erected outside the Shanksville firehouse near the crash site of United Airlines Flight 93. Portions of the South T

In cryptography, encryption is the process of encoding a message or information in such a way that only authorized parties can access it and those who are not authorized cannot. Encryption does not itself prevent interference but denies the intelligible content to a would-be interceptor. In an encryption scheme, the intended information or message, referred to as plaintext, is encrypted using an encryption algorithm–a cipher–generating ciphertext that can be read only if decrypted. For technical reasons, an encryption scheme uses a pseudo-random encryption key generated by an algorithm, it is in principle possible to decrypt the message without possessing the key, for a well-designed encryption scheme, considerable computational resources and skills are required. An authorized recipient can decrypt the message with the key provided by the originator to recipients but not to unauthorized users. In symmetric-key schemes, the encryption and decryption keys are the same. Communicating parties must have the same key.

An example of a symmetric key is the German military's Enigma Machine. There were key settings for each day; when the Allies figured out how the machine worked, they were able to decipher the information encoded within the messages as soon as they could discover the encryption key for a given day's transmissions. In public-key encryption schemes, the encryption key is published for anyone to use and encrypt messages. However, only the receiving party has access to the decryption key. Public-key encryption was first described in a secret document in 1973. Although published subsequently, the work of Diffie and Hellman was published in a journal with a large readership, the value of the methodology was explicitly described and the method became known as the Diffie Hellman key exchange. A publicly available public key encryption application called Pretty Good Privacy was written in 1991 by Phil Zimmermann, distributed free of charge with source code. PGP was purchased by Symantec in 2010 and is updated.

Encryption has long been used by governments to facilitate secret communication. It is now used in protecting information within many kinds of civilian systems. For example, the Computer Security Institute reported that in 2007, 71% of companies surveyed utilized encryption for some of their data in transit, 53% utilized encryption for some of their data in storage. Encryption can be used to protect data "at rest", such as information stored on computers and storage devices. In recent years, there have been numerous reports of confidential data, such as customers' personal records, being exposed through loss or theft of laptops or backup drives. Digital rights management systems, which prevent unauthorized use or reproduction of copyrighted material and protect software against reverse engineering, is another somewhat different example of using encryption on data at rest. Encryption is used to protect data in transit, for example data being transferred via networks, mobile telephones, wireless microphones, wireless intercom systems, Bluetooth devices and bank automatic teller machines.

There have been numerous reports of data in transit being intercepted in recent years. Data should be encrypted when transmitted across networks in order to protect against eavesdropping of network traffic by unauthorized users. Conventional methods for permanently deleting data from a storage device involve overwriting the device's whole content with zeros, ones or other patterns – a process which can take a significant amount of time, depending on the capacity and the type of storage medium. Cryptography offers a way of making the erasure instantaneous; this method is called crypto-shredding. An example implementation of this method can be found on iOS devices, where the cryptographic key is kept in a dedicated'effaceable storage'; because the key is stored on the same device, this setup on its own does not offer full privacy or security protection if an unauthorized person gains physical access to the device. Encryption is an important tool but is not sufficient alone to ensure the security or privacy of sensitive information throughout its lifetime.

Most applications of encryption protect information only at rest or in transit, leaving sensitive data in cleartext and vulnerable to improper disclosure during processing, such as by a cloud service for example. Homomorphic encryption and secure multi-party computation are emerging techniques to compute on encrypted data. In response to encryption of data at rest, cyber-adversaries have developed new types of attacks; these more recent threats to encryption of data at rest include cryptographic attacks, stolen ciphertext attacks, attacks on encryption keys, insider attacks, data corruption or integrity attacks, data destruction attacks, ransomware attacks. Data fragmentation and active defense data protection technologies attempt to counter some of these attacks, by distributing, moving, or mutating ciphertext so it is more difficult to identify, corrupt, or destroy. Encryption, by itself, can protect the confidentiality of messages, but other techniques are still needed to protect the integrity and authenticity of a message.

Authenticated encryption algorithms are designed to provide both encryption and integrity protection together

Sam Saturday is a British television police procedural drama series, broadcast between 27 June and 8 August 1992. The six-part series produced by Cinema Verity in association with LWT, broadcast on ITV, follows the work of DI Sam Sterne, a Jewish police detective, as he struggles to balance the demands of the job with his private life; the series was created by writer and director Alvin Rakoff, was produced by the production company of executive producer Verity Lambert. The series was just one of a number of commissions made by LWT controller of drama Nick Elliott in 1991, following the announcement that both The Ruth Rendell Mysteries and Inspector Morse were to cease production; the first episode of the series finds Sterne moving back in with his mother, after a messy divorce. Three episodes of the series were written by acclaimed writer Stanley Price. Despite good reception, in the light of both Inspector Morse and The Ruth Rendell Mysteries returning to the ITV schedules, a second series was never commissioned.

In 2013, Kaye stated in an interview that he was grateful to have "his own series at 30", explained how the series allowed him to break through into other television roles, as well as securing a leading West End role within six months of the programme's broadcast. Ivan Kaye as DI Sam Sterne Peter Armitage as Jim Butler Doreen Mantle as Rita Sterne Dennis Victory as Mike Michael Elwyn as CDI Simpson David Fleeshman as Michael Sterne Simon Slater as DI Griffiths Lauren Jacobs as Miriam Sterne Paul Opacic as DC Knights Helen Levien as WPC Daniels Sam Saturday on IMDb