Sortable encryption

When the data is fully end-to-end encrypted, nobody even the server can decrypt and read / analyze the data. To do range queries like sort table by last name, the server must know the decrypted value. The encryption only works in groups.

With the sortable encryption it is not necessary anymore. The encrypted produces numbers that follow the order of the plaintext and can be used with any database or backend.

Like: encrypt(1) < encrypt(2) < encrypt(3) < encrypt(5000)

Now it is possible to do range queries or sort rows without decrypting them.

WARNING

The encryption is not as secure as the symmetric or asymmetric encryption.

This is why sentc never encrypts the whole plaintext.

You can encrypt numbers or strings. Numbers are fully encrypted, for strings only the first four characters will be encrypted, and the rest gets ignored.

Use this technic only in combination with the symmetric encryption to encrypt a value symmetrically so the user can decrypt it and also encrypt it with the sortable encryption to do range queries in your backend.

Encrypt a number

The maximum number to encrypt is 65532.

const a = group.encryptSortableRawNumber(262);
const b = group.encryptSortableRawNumber(263);
const c = group.encryptSortableRawNumber(65321);

//a < b < c

For flutter, it is a future

final a = await group.encryptSortableRawNumber(262);
final b = await group.encryptSortableRawNumber(263);
final c = await group.encryptSortableRawNumber(65321);

//a < b < c

use sentc::keys::StdGroup;

fn example(group: &StdGroup)
{
	let a = group.encrypt_sortable_raw_number(262).unwrap();
	let b = group.encrypt_sortable_raw_number(263).unwrap();
	let c = group.encrypt_sortable_raw_number(65321).unwrap();

	//a < b < c
}

To get more information about how the value is encrypted, you can use this function instead:

It returns the number as the first param, the used algorithms and the used key id.

const [number, alg, key_id] = group.encryptSortableNumber(262);

It returns the number as the first param, the used algorithms and the used key id.

final out = await group.encryptSortableNumber(262);

final number = out.number;
final alg = out.alg;
final keyId = out.keyId;

use sentc::keys::StdGroup;

fn example(group: &StdGroup)
{
	let out = group.encrypt_sortable_number(262).unwrap();
}

Encrypt a string

Only the first four characters will be used to encrypt the string the rest will be ignored.

Strings with umlauts or other non-English characters are not supported. Alternatively you can use the english version like ö ot oe

But you can write your own function that creates a number and encrypts the number.

const a = group.encryptSortableRawString("abc");
const b = group.encryptSortableRawString("dfg");
const c = group.encryptSortableRawString("hij");

//a < b < c

For flutter, it is a future

final a = await group.encryptSortableRawString("abc");
final b = await group.encryptSortableRawString("dfg");
final c = await group.encryptSortableRawString("hij");

//a < b < c

use sentc::keys::StdGroup;

fn example(group: &StdGroup)
{
	let a = group.encrypt_sortable_raw_string("abc", None).unwrap();
	let b = group.encrypt_sortable_raw_string("dfg", None).unwrap();
	let c = group.encrypt_sortable_raw_string("hij", None).unwrap();

	//a < b < c
}

To get more information from the encrypted strings, use this function:

It returns the number as the first param, the used algorithms and the used key id.

const [number, alg, key_id] = group.encryptSortableString("abc");

It returns the number as the first param, the used algorithms and the used key id.

final out = await group.encryptSortableString("abc");

final number = out.number;
final alg = out.alg;
final keyId = out.keyId;

use sentc::keys::StdGroup;

fn example(group: &StdGroup)
{
	let out = group.encrypt_sortable_string("abc").unwrap();
}