Each side had three overall goals in this battle. The first was to attack the supply lines of the other side. The second was to keep open its own supply lines, the Axis to their own armies in North Africa and the Allies to supply the island of Malta. The third was to destroy the ability of the opposing navy to wage war at sea.
Outside of the Pacific ocean, the Mediterranean saw the largest conventional naval warfare during the war. In particular, Allied forces struggled to supply and retain the key naval and air base of Malta.
Italian warships had a general reputation as well-designed and good-looking. But some Italian cruiser classes were rather deficient in armour. All Italian warships lacked radar for most of the war, although this was partly offset by their good "rangefinder" and "fire-control" systems. In addition, whereas Allied commanders at sea had discretion on how to act, Italian commanders were closely and precisely governed by Italian Naval Headquarters ("Supermarina"). This could lead to action being avoided when the Italians had a clear advantage (e.g., During "Operation Hats"). Italian Naval Headquarters was conscious that the British could replace ships lost in the Mediterranean, whereas Italian Navy resources were limited and there was a terrible lack of fuel.
The Italian Navy entered the war with only one year of fuel required to operate normally. By 1943 the lack of fuel prevented naval operations far away from the coasts of Italy.
The Allies had "Ultra" intercepts from Bletchley Park, which predicted the Italian movements, and radar, which enabled them to locate the ships and to range their weapons at distance and at night. The better air reconnaissance skills of the "Fleet Air Arm" and their close collaboration with surface units were other major causes of the initial Italian defeats (like in the "Battle of Cape Matapan").
The Axis forces in this campaign were:-
The Allied forces in this campaign were:-
On 10 June 1940, Italy declared war on Britain and France. On the following day, Italian bombers attacked Malta on what was to be the first of many raids.
The first clash between the rival fleets, the Battle of Calabria, took place on 9 July 1940, just four weeks after the start of hostilities. This was inconclusive (neither side won), and was followed by a series of small ship actions (the battle of the "Espero" convoy, battle of Cape Spada) during the autumn.
In spring 1940 the British Royal navy attacked at Mers el Kebir (Algeria) the French navy of Vichy, sinking two battleships and other minor ships.
In November, the RN mounted an aerial attack on the Italian fleet in Taranto harbour, crippling three capital ships and changing the balance of power in the Mediterranean.
Three months later the fleets clashed again at the Battle of Cape Matapan. This was a major Allied victory; three Italian cruisers were sunk, and a battleship damaged in a two-day battle ending in a night action.
Following this the Allies suffered heavy losses in the Battle of Crete, supporting the army when the island was invaded by the Germans.
In spring 1941 the Greek and Yugoslavian navy were destroyed and/or made captive by the Italians (with help from the German air force) during the Italo-German war in the western Balkans against Greece and Yugoslavia.
Following the battle of Crete in the summer of 1941, the Royal Navy got the better of things in the central Mediterranean in a series of successful convoy attacks, (such as the "Duisburg" convoy and the Battle of Cape Bon) until the events around the First Battle of Sirte and the Raid on Alexandria in December swung the balance of power in the Axis favour.
The Italian Navy's most successful attack was when divers planted mines on British battleships during the raid on Alexandria harbour (19 December 1941). HMS "Queen Elizabeth" and HMS "Valiant" were sunk (but ten months later raised and returned to active service). During those ten months the Italian Navy enjoyed a temporary control of the Mediterranean sea (called by Mussolini's propaganda the "Mare Nostrum", meaning "our sea").
A series of hard fought convoy battles (Second Battle of Sirte in March, Operations Harpoon and Vigorous in June, and Operation Pedestal in August) were victories for the Axis but ensured Malta's survival, until the Allies regained the advantage in November 1942.
In Sept 1943 with the Italian collapse and the surrender of Italian fleet, naval actions in Mediterranean became restricted to actions against U-boats and by small craft in the Adriatic and Aegean seas.
The following are the major amphibious operations staged during the Battle of the Mediterranean:
Cryptographic hash function
A cryptographic hash function is a hash function which takes an input (or 'message') and returns a fixed-size string of bytes. The string is called the 'hash value', 'message digest', 'digital fingerprint', 'digest' or 'checksum'.
The ideal hash function has three main properties:
Functions with these properties are used as hash functions for a variety of purposes, not only in cryptography. Practical applications include message integrity checks, digital signatures, authentication, and various information security applications.
A hash function takes a string of any length as input and produces a fixed length string which acts as a kind of "signature" for the data provided. In this way, a person knowing the "hash value" is unable to know the original message, but only the person who knows the original message can prove the "hash value" is created from that message.
A cryptographic hash function should behave as much as possible like a random function while still being deterministic and efficiently computable. A cryptographic hash function is considered "insecure" from a cryptographic point of view, if either of the following is computationally feasible:
An attacker who can find any of the above computations can use them to substitute an authorized message with an unauthorized one.
Ideally, it should be impossible to find two different messages whose digests ("hash values") are similar. Also, one would not want an attacker to be able to learn anything useful about a message from its digest ("hash values"). Of course the attacker learns at least one piece of information, the digest itself, by which the attacker can recognise if the same message occurred again.
In various standards and applications, the two most commonly used hash functions are MD5 and SHA-1.
In 2005, security defects were identified showing that a possible mathematical weakness might exist, like attacks, and recommending a stronger hash function.
In 2007 the National Institute of Standards and Technology announced a contest to design a hash function which will be given the name SHA-3 and be the subject of a FIPS standard.
Data integrity
Data integrity is a term used in computer science and telecommunications that can mean:
Simply, data integrity is to make sure that data is "consistent" and "correct".
Cryptosystem
There are two different meanings of the word cryptosystem.
In this meaning, the term cryptosystem is used as shorthand, or as an abbreviation for "cryptographic system". A cryptographic system is any computer system that involves cryptography. Such systems include for instance, a system for secure electronic mail which might include methods for digital signatures, cryptographic hash functions, key management techniques, and so on.
In this meaning, a cryptosystem refers to a set of algorithms needed to implement a method of encryption and decryption.
Typically, a cryptosystem consists of three algorithms: