- •The detection process
- •The Universal algorithm
- •The “Percussive” algorithms
- •The Melodic algorithm
- •The “Polyphonic” algorithms
- •Switching algorithms
- •Automatic or manual algorithm selection
The ideal algorithm for each track– Choosing from different algorithms to let your creativity flow – and to obtain perfect sound quality. Shown here: Melodyne 5 studio, smaller editions may differ.
For the display and editing of different types of audio material, Melodyne employs different algorithms. Here, we outline which algorithms are available and for which types of audio material each is used.
The detection process
Melodyne analyzes the audio material to find the notes it contains and offer them to you for editing. We call this process “detection”.
In the course of the detection process, Melodyne itself takes a view as to what kind of material it is confronted with and decides which algorithm to use for the display and playback of the notes. You can tell which algorithm is selected at any given time by the check mark in the Algorithm menu as well as by the blobs in the Note Editor. Please bear in mind, however, that the detection process – in particular in the case of polyphonic audio material – cannot, for reasons that have to do with immutable principles, always deliver perfect results. Since a musically correct analysis of the recorded material is the most important precondition for efficient editing and convincing acoustic results, we recommend you to check the results of the detection systematically and make whatever corrections in Note Assignment Mode are necessary.
A brief overview: Which algorithm for which type of material?
To obtain the most suitable and detailed editing possibilities, for the following sound sources, the following algorithms are generally used:
- Singing, speech, saxophone, flute, monophonic bass etc.: "Melodic"
- Drum and percussion sounds or loops, and other percussive sounds with no significant pitched components: "Percussive"
- 808-kicks and -toms, tabla and similar percussive sounds with a pitched component: "Percussive Pitched"
- Pianos, strings, organs, guitars and other instruments capable of sounding more than one note at a time, where you wish to edit individual notes: "Polyphonic Decay" or "Polyphonic Sustain" (depending upon their sound or the playing techniques employed e.g. in the case of strings: pizzicato or legato)
- Rhythm guitars (funky guitars or distorted riffs and similar sounds), where you only wish to time-stretch or transpose them and no access to individual notes is required: "Universal"
- Loops featuring multiple instruments, or complete mixes, that you wish to time-stretch, quantize or transpose: "Universal"
- Experimental sound design (regardless of the original sound source): potentially any algorithm with extreme settings but primarily "Polyphonic Decay" or "Polyphonic Sustain"
The Universal algorithm
The Universal algorithm is particularly suitable for complex signals containing both percussive and tonal elements. If, for example, you wish to alter the pitch, timing or tempo of an entire piece of music, this algorithm will deliver the best sound quality.
The Universal algorithm, like the Percussive one, displays all the detected notes at the same pitch. The Pitch Ruler displays no note names, merely relative values for the semitones, and the scale functions are deactivated. The Universal algorithm completes the detection process very quickly and also consumes far fewer resources than the Polyphonic algorithm. It represents a good choice, therefore for recordings of individual instruments of all kinds that you intend simply to speed up, slow down or transpose. Tracks, in other words, for which you do not need bells and whistles such as DNA or Melodyne’s scale functions. Please note that with files that have been detected using the Universal Algorithm, the Attack Speed Tool cannot be used. Attack speed handles will therefore not be displayed for the corresponding blobs and the Attack Speed field in the Note Inspector will be grayed out. Please note that “Universal” is never used automatically for the detection; it must be selected manually if required.
The “Percussive” algorithms
The "Percussive" algorithms are suitable for recordings of drums and other percussion instruments but also noise and atmospheric effects as well as other material in which Melodyne cannot detect any clear pitch in the sounds. In this case, successive drum strokes (for example) are distinguished, but they are all displayed at the same pitch. The blobs can still be raised or lowered, however the Pitch Ruler does not display the names of any notes but simply relative values in semitones. The scale functions are deactivated.
Some percussion instruments, however, do have what can be understood as a melodic capability, in that many of their sounds have a perceived pitch. Certain 808 kick drums, for example, are clearly tuned to the bass. The berimbau, too, for all the percussive character of its sound, plays recognizable melodies – as does the tabla. It is for such instruments – instruments that are in fact percussive yet still somehow also melodic – that the "Percussive Pitched" algorithm is intended. Here the detected sounds are separated and assigned to individual pitches. This makes it easy to adjust the tuning of an 808 kick drum, berimbau or tabla to the piece of music in question.
Whilst the Percussive and Universal algorithms are similar in terms of the way the blobs are handled and displayed – just as the Percussive Pitched and Melodic algorithms seem similar at first sight – the two percussive algorithms in fact operate in a different way internally from their optical “twins”, as they are optimized for various aspects of percussive sounds and consequently deliver their most convincing sound quality when dealing with material of a predominantly percussive nature. When dealing with non-percussive sources, however, such as the human voice, guitars, pianos and so forth, they are at a distinct disadvantage compared with the other algorithms, which are optimized for sounds with a distinct pitch.
In case of doubt – with instruments seeming to fall (or perhaps alternate) between the stools “percussive” and “melodic” – the best policy is to try each algorithm in turn.
Another distinctive feature of the “Percussive Pitched” algorithm, which it shares only with the “Melodic” algorithm, is that Melodyne is able here to detect, display and permit the editing of sibilants. With the “Melodic” algorithm, however, this happens automatically, whereas with the “Percussive Pitched” algorithm, sibilant control is by default switched off. To switch it on, go to Note Assignment Mode and check “Sibilant Handling” in the Algorithm Inspector. You can learn more about this here.
The Melodic algorithm
Melodic material is monophonic, by which we mean it is such that only one note is ever sounding at any given instant. Please bear in mind, however, that reverberation can cause notes to overlap even in monophonic material, creating, in effect, a kind of polyphony. If melodic material is to be edited in Melodyne, therefore, you should aim for as clean and “dry” (reverberation-free) a recording as possible.
The blobs representing notes in melodic material are displayed at different pitches. Whether the blobs are isolated or joined to other blobs depends on the way they were played or sung: staccato or legato.
The “Melodic” algorithm is predestined for lead vocal tracks, as these are invariably monophonic; for there to be polyphony, there would have to be at least two singers. Furthermore, this algorithm takes into account the sibilants invariably heard in vocal parts. In the term ‘sibilants’, Melodyne includes not only consonants and digraphs such as “s” and “ch”, but also word fragments like “k” and “t” as well as the sound of the vocalist inhaling or exhaling between words.
Such sounds, which Melodyne identifies automatically and displays hatched, share one peculiarity in nature: There is no way singers can give them a particular pitch, so they remain unaffected by melodic changes. This behavior is preserved perfectly by Melodyne’s “Melodic” algorithm: Sibilants remain unaltered even when the word or syllable to which they belong is shifted upwards or downwards in pitch.
Let’s say the word is “sweet”, and we move the blob that represents the note in question upwards or downwards. Whilst the entire note will appear to move, acoustically this will not be the case as the “S” at the beginning and the “T” at the end will sound exactly the same after the pitch shift as they did before; only the “wee” in the middle will change pitch – in the direction, and by the amount, of the blob movement.
When editing timing, too, you will notice that the sibilants (indicated by the hatching) are never unnaturally squeezed or stretched.
This intelligent treatment of sibilants is vital to achieving natural-sounding correction of intonation and timing. Melodyne even takes into account the borderline cases that occur in nature, where sibilants and pitched components are heard simultaneously (rather than successively, as was the case earlier with the word “sweet”).
In Note Assignment Mode, you can edit the results of the detection and (if need be) alter the length of the sibilants detected or deactivate sibilant detection for an audio file in the Algorithm Inspector.
The “Polyphonic” algorithms
In Melodyne, thanks to DNA Direct Note Access, notes can be detected and edited within recordings even of polyphonic instruments such as the piano or guitar – including the individual notes of which chords are composed. When the Polyphonic algorithm is used, the blobs are displayed in a similar manner to those of monophonic material, with the obvious difference that the blobs are stacked vertically (at their respective pitches) whenever a chord or harmonic interval sounds.
There are two versions of the Polyphonic algorithm.
- Polyphonic Sustain is suitable for a wide range of polyphonic audio material in which the start of each note does not differ significantly from the rest, as is the case with string instruments played legato and organ music.
- Polyphonic Decay is a variation of that algorithm designed for instruments or playing techniques where the start of each note is markedly different from what follows, examples being string instruments played pizzicato, guitars and pianos.
Please note that DNA is intended for polyphonic instruments recorded singly, as it separates notes by pitch – not by instrument. This means that if you were to record two different instruments on the same track, whenever they played the same note, a ‘single’ blob would appear (representing the combined sound of both instruments) rather than a separate blob for each instrument playing the note.
You can at any time select a different algorithm to that chosen automatically for you by Melodyne. You might want to do this, for example, if you find that the material has not been interpreted in a way that suits your editing needs. To do this, while playback is halted, select the algorithm you prefer from the Algorithm menu. Melodyne will reinterpret the material in the light of your choice and adjust the display accordingly.
Note: when you do this, any editing of the same track performed prior to switching algorithms, including any copying of notes, will be lost (copied notes on other tracks are retained) . The right time to decide which algorithm you wish to use, therefore, is before you begin editing.
In the plug-in implementation of Melodyne, the choice of algorithm applies per transfer, whereas in the stand-alone implementation and an ARA DAW, it applies per audio file in the document being edited – collectively, we describe all such material as ‘audio sources’. Before you can change the algorithm applied to a particular audio source, you must first select one or more notes belonging exclusively to it. If you have selected no notes, or notes from two different audio sources, the Algorithm menu will be grayed out. In such cases, reduce your selection to notes belonging to one audio source only and it will be possible to switch algorithms.
A special feature of the stand-alone implementation: When you switch algorithms, triggering a fresh detection, Melodyne looks at the status of the Auto Stretch switch: if the Auto Stretch function is activated, once the new detection is complete, the tempo of the file will also be adjusted: if Auto Stretch is not selected, the original tempo of the file will be retained.
NB: There is some audio material that cannot be detected using the polyphonic algorithms because it contains too few tonal components. If in the case of such material you have chosen one of the polyphonic algorithms as the default (see below), the polyphonic detection process will be interrupted and a fresh detection of the material using the Percussive Algorithm, which is better suited to it, will commence. If you wish in such cases, when this detection is complete, you can still switch to Universal or Melodic.
Automatic or manual algorithm selection
By default, Melodyne makes its own determination, based on the characteristics of the sound, as to which is the best algorithm to apply, distinguishing between these types of material:
- Percussive material, in which case the “Percussive” algorithm is selected.
- Monophonic melodic material, in which case the “Melodic” algorithm is selected.
- Polyphonic material, in which case, depending upon the audio material, either the “Polyphonic Decay” or the “Polyphonic Sustain” algorithm is selected.
If, however, in an instance of the plug-in implementation of Melodyne or on a track of the stand-alone implementation material has already been detected, when new material is transferred to that instance or a new file dragged into the track of the stand-alone implementation, Melodyne will use the same algorithm for the new material as it used for the old – even if Automatic is selected.
Overruling the Automatic setting in this way is designed to ensure maximum consistency in the detection and avoid all risk of one of the transfers from a vocal track suddenly being interpreted as percussive. If, however, you have altered the algorithm of a transfer or file manually, the automation kicks in again afterwards, and no further attention is paid in the case of further transfers or files to already detected material.
This rule only applies when Automatic is preselected as the algorithm and it does not apply when, in the stand-alone implementation of Melodyne, you first drag a file into the document for which you have already saved additional information regarding the algorithm and note detection. (From Note Assignment mode in the stand-alone implementation of Melodyne, it is possible to store this type of assignment data in an audio file.)
By setting a different default via the Algorithm menu, you can prevent Melodyne selecting an algorithm automatically for the detection. This can be useful if, for example, you regularly want to edit particular files using the Percussive algorithm but Melodyne, each time they are opened, is interpreting the material as polyphonic. By preselecting the Percussive algorithm in such cases you can save time, as you will no longer have to wait needlessly as Melodyne performs its polyphonic analysis, only to discard the results moments later when you manually select the Percussive algorithm.
Do not forget, however, when you no longer need to impose your choice of algorithm on Melodyne, to restore Automatic as the default setting. Otherwise, since Melodyne remembers your default selection even after you have quit the program, you might be surprised to discover when the program is next launched that your vocals have been interpreted as percussive.
You will find further tips on working with these algorithms in the Melodyne Training section.
Melodyne's algorithms are optimized for particular types of material. For this reason, Melodyne selects automatically “Melodic” for a vocal or bass track, “Polyphonic” for a guitar or string track, “Percussive” for drums, and so on. These are generally the right choices.What are the algorithm modes choices in Melodyne? ›
Melodyne's algorithms are optimized for particular types of material. For this reason, Melodyne selects automatically “Melodic” for a vocal or bass track, “Polyphonic” for a guitar or string track, “Percussive” for drums, and so on. These are generally the right choices.What is the difference between sustain and decay in Melodyne? ›
Polyphonic Decay is similar to the original polyphonic algorithm, whereas Polyphonic Sustain is designed to work with sounds such as legato strings that do not contain clear note attacks.How does Melodyne 5 work? ›
Melodyne 5 studio gives you direct access to individual notes within your recordings, allowing you to edit their pitch, position, duration and other musical parameters in an intuitive way.What is the difference between pitch center and pitch drift? ›
Pitch Center aligns the recorded notes with the actual pitch. It centers the note so it's not sharp or flat. When a singer holds out a note, the pitch tends to drift up or down. Pitch Drift keeps the note in tune throughout the course of the note.What are algorithm modes? ›
There are two basic types of symmetric algorithms: block ciphers and stream ciphers. Block ciphers operate on blocks of plaintext and ciphertext—usually of 64 bits but sometimes longer.What is track mode vs clip mode Melodyne? ›
The left-hand button activates Track Mode; the button to the right of it, Clip Mode. Track Mode lets you see the entire contents of the track opened in Melodyne, however many clips it is composed of in the DAW. The clip borders are indicated in Melodyne by vertical gray lines.What is the difference between pitch drift and modulation in Melodyne? ›
The term 'pitch modulation' covers rapid and usually intentional variations in pitch such as trills or vibrato. 'Pitch drift' is our term for slow fluctuations in pitch of the kind that are usually unintentional and symptomatic of poor technique.What does pitch drift do in Melodyne? ›
Training Melodyne 4 studio - Producing skills: Lead vocals. Inside tip: Pitch Drift. With the Pitch Drift Tool, you can lessen a tendency for the Pitch Curve to drift up or down in the course of the note. This is done by “tipping” the Pitch Curve.What is formant in Melodyne? ›
Using the Formant tool - Melodyne Tutorial
- [Voiceover] The formant tool allows you to adjust the tambour of the sound. This can be useful for altering the sound when make large changes in pitch. For example, if you're taking a note that was performed lower in a singer's range and shifting the pitch up.
Melodyne is often used in song production, but most often it's not the singers who use this software but their mix engineers. As you know, the most important thing in a song is emotion and the right vocal expression.Is anything better than Melodyne? ›
The 4 Best Paid Melodyne Alternatives
Antares Auto-Tune. Waves Tune. Soundtoys Little Alterboy. Logic Pro Flex Pitch.
Another consideration to take is how you want to use pitch-correction. In the studio, Melodyne really has no competition for accuracy, but if you need tuning in a live scenario you need something that processes the audio in real-time so Auto-Tune is your only choice.What are the different types of pitch shifting? ›
There are two kinds of pitch-shifters: monophonic or polyphonic. Monophonic pitch shifters process one layer of pitch whilst polyphonic pitch shifter process multipul layers of pitch. This means monophonic pitch shifter process single notes better whilst polyphonic process chords much better.What is the difference between Hertz and pitch? ›
The pitch of sound is determined by the frequency of vibration of the sound waves that produce them. A high frequency (e.g., 880 Hz) is seen as a high pitch, while a low frequency (e.g., 55 Hz) is regarded as a low pitch.What is the difference between diametrical pitch circular pitch and module? ›
While both specifications define the size of the gear teeth, module and diametral pitch are calculated differently, with module (sometimes referred to as metric pitch) being the metric sizing standard and diametrical pitch being the Imperial (inch) sizing method.What are the 4 types of algorithm? ›
There are four types of machine learning algorithms: supervised, semi-supervised, unsupervised and reinforcement.What are the 3 standard algorithms? ›
- bubble sort.
- merge sort.
Track Mode is designed for use on closed circuit driving courses only. It is the driver's responsibility to drive safely and ensure others are not endangered. Track Mode is designed for use by experienced track drivers familiar with the course. Do not use on public roads.What does the note assignment mode do in Melodyne? ›
By contrast with normal editing mode: In Note Assignment Mode, the separation tools are not used to reshape the music but to edit the analysis or “detection”. The object is to ensure that the blobs represent as accurately as possible the actual music.
Right-click on the title bar of a region and select “Bounce to hard disk”. Now enter a name followed by the audio resolution parameters. Under no circumstances check “Bypass Effect Plug-ins” as this would cause your Melodyne editing to be ignored.Is pitch correction better than Auto-Tune? ›
While pitch correction tools are primarily about fixing minor imperfections in vocal recordings, Auto-Tune can also be used as a stylistic choice, transforming the singer's voice into another instrument that can be edited and altered indefinitely.What is the difference between Formant and pitch shift? ›
Pitch-shifters usually transpose the signal in semitones up or down. Formant shifters do not affect the pitch or timing of a segment. Formant shifters change only the sound of the voice, and you can have a low or high-pitched voice without changing the key.What does Formant shift do? ›
Formant shifting allows you to alter the tone of each voice without changing the pitch or timing, so you can perfectly preserve the original performance while still giving the track its own sonic character. Just be careful—adjusting the formants too much can create unnatural effects.What is the difference between harmonic and formant? ›
Harmonics are considered the source of the sound. Formants come from the vocal tract. The air inside the vocal tract vibrates at different pitches depending on its size and shape of opening.
Thus the first formant F1 has a higher frequency for an open or low vowel such as [a] and a lower frequency for a closed or high vowel such as [i] or [u]; and the second formant F2 has a higher frequency for a front vowel such as [i] and a lower frequency for a back vowel such as [u].
|F1||first formant||500 Hz|
|F2||second formant||1500 Hz|
|F3||third formant||2500 Hz|
Melodyne is a plug‑in, so the editing it does is non‑destructive until you decide to render the audio.Where should Melodyne be in vocal chain? ›
So where should you put Melodyne in the signal chain then? Generally speaking, Melodyne should always be the first plugin in your signal chain. You want Melodyne to transfer the cleanest audio signal possible, that way you don't highlight any artifacts or sounds created by things like EQ, compression, or other effects.Why does Melodyne sound robotic? ›
Quick guess: If you're getting robotic results, it's probably because you're double-clicking notes with the Pitch Modulation tool selected. The result is 100% modulation correction (flattened pitch). Use drag, not double-click.
Editor adds Polyphony and Tempo Editing. Studio adds Multi-track, Sound Editor and Quantize-to-track functionality.Can Melodyne remove vocals? ›
The next option is to pay for software that will help you to remove vocals from a song. One professional option is Melodyne. They have a 30 free trial to see if it is for you. It is neat software and is well worth taking a look into the methods behind using it.Can you use Melodyne without a DAW? ›
When you install the Melodyne plug-in, it will also install the standalone app. The standalone app lets you record audio directly into the software. You can also import any existing audio file. Standalone mode is especially useful if you don't use a DAW or need to edit an individual track.What Auto-Tune do professionals use? ›
Antares Autotune Pro by Antares Audio Technologies
Their software is used as the standard when it comes to the big leagues in many of the top recording studios worldwide. This is due to its ease of use and trusted reputation. After all, Antares do actually own the trademark “Autotune”.
Autotune uses software algorithms to quickly change the current pitch of a note to the desired pitch. This is not something a human being can do, therefore it tends to sound quite unnatural, even robotic.What are the 4 levels of pitch? ›
In the work of Trager and Smith there are four contrastive levels of pitch: low (1), middle (2), high (3), and very high (4).What are the 2 types of pitch perception? ›
There are two broad categories of pitch-perception models: place or spectral models consider that pitch is mainly related to the Fourier spectrum of the stimulus, whereas for periodicity or temporal models its characteristics in the time domain are more important.Does speeding up a song change the pitch? ›
Slowing down the recording to increase duration also lowers the pitch, while speeding it up for a shorter duration respectively raises the pitch, creating the so-called Chipmunk effect.What is the best pitch frequency? ›
In 1939, the International Organization for Standardization recognized 440 Hz as the standard concert pitch. This is how A4 = 440 Hz became the tuning standard of all instruments we use today, both analog and digital.What Hz is perfect pitch? ›
Perfect Pitch: 432 Hz Music and the Promise of Frequency.
Since sound is a wave, it has all of the properties attributed to any wave, and these attributes are the four elements that define any and all sounds. They are the frequency, amplitude, wave form and duration, or in musical terms, pitch, dynamic, timbre (tone color), and duration.What is the difference between DP and module? ›
Both represent the size of the gear tooth, the module is used in the metric system, the larger the number, the larger the gear tooth; DP is used in the imperial system, the higher the number, the smaller the gear tooth.Is gear module the same as pitch? ›
Modules are equal to the pitch diameter divided by the number of teeth in a single gear. Another difference between diametrical pitches and modules is that the pitch diameter is always measured in inches, while modules are measured in millimeters.How do you convert pitch diameter to module? ›
Diametral pitch is always in inches. Module pitch is always in millimeters. 1 Diametral pitch = 25.400 Module.What are different algorithm modes explain those which are applied on block ciphers? ›
Introduction to Block Cipher modes
There are five types of operations in block cipher modes, ECB (Electronic Code Block) mode, CBC (Cipher Block Chaining) mode, CFB (Cipher Feedback) mode, OFB (Output Feedback) mode and CTR ( Counter) mode.
- Encryption modes. ...
- ECB (Electronic Code Book) mode. ...
- Padding. ...
- CBC (Cipher Block Chaining) mode. ...
- Initialization vectors. ...
- CFB (Cipher Feedback) mode. ...
- OFB (Output Feedback) mode. ...
- CTR (Counter) mode.
Secret-key cryptography is also called symmetric cryptography because the same key is used to both encrypt and decrypt the data. Well-known secret-key cryptographic algorithms include Advanced Encryption Standard (AES), Triple Data Encryption Standard (3DES), and Rivest Cipher 4 (RC4).What is the difference between RC4 and RC5 algorithm? ›
RC4 is a variable key-size stream cipher with byte-oriented operations. The algorithm uses a random permutation for data. RC5 is a parameterized algorithm implementing a 32-, 64- or 128-bit blocks, a variable key size, and a variable number of rounds.What is the cast 128 algorithm? ›
CAST-128 is a 12- or 16-round Feistel cipher that has a blocksize of 64 bits and a keysize of up to 128 bits; it uses rotation to provide intrinsic immunity to linear and differential attacks; it uses a mixture of XOR, addition and subtraction (modulo 2**32) in the round function; and it uses three variations of the ...What is the difference between RC5 and Blowfish algorithm? ›
Blowfish has a 64-bit block size and a variable key length of between 32 bits and 448 bits. RC5 uses block sizes of 32 bits, 64 bits or 128 bits and variable key lengths of between 0 and 2040 bits.
CFB mode is very similar to CBC, but the primary difference is that CFB is a stream mode. It uses feedback, which is the name for chaining when used in stream modes, to destroy patterns. Like CBC, CFB uses an initialization vector and destroys patterns, and so errors propagate.Which is the most widely used block cipher algorithm? ›
AES - A US Federal Government standard since 2002, AES or Advanced Encryption Standard is arguably the most widely used block cipher in the world. It has a block size of 128 bits and supports three possible key sizes - 128, 192, and 256 bits.What are the 3 main types of cryptographic algorithms? ›
- Hash functions.
- Symmetric-key algorithms.
- Asymmetric-key algorithms.
- Hash Functions.
- Symmetric-Key Algorithms for Encryption and Decryption.
AES (Advanced Encryption Standard, also known as Rijndael) is the most popular and widely used symmetric encryption algorithm in the modern IT industry. This is because AES is proven to be highly secure, fast and well standardised and very well supported on virtually all platforms.What is the difference between asymmetric and symmetric algorithms? ›
The main difference is that symmetric encryption uses the same key to encrypt and decrypt data. In contrast, asymmetric encryption uses a pair of keys – a public key to encrypt data and a private key to decrypt information. Both symmetric and asymmetric algorithms provide authentication capability.What are the 2 algorithms of the asymmetric key? ›
The two main uses of asymmetric-key algorithms are public-key encryption and digital signatures.What is the strongest key algorithm? ›
AES 256-bit encryption is the strongest and most robust encryption standard that is commercially available today.What are the 2 main types of cryptographic algorithms? ›
Cryptography is broadly classified into two categories: Symmetric key Cryptography and Asymmetric key Cryptography (popularly known as public key cryptography).
Cryptography is classified into two categories based on the types of keys and encryption algorithms: Symmetric Key Cryptography (Secret key) Asymmetric Key Cryptography (Public key)